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Transcript of Car Templates
Working with Templates
Adams/Car
134
Template Basics
Your template-based product's library includes a variety of templates. Templates define the topology,
major role, and default parameters for subsystems. This tab includes template information that is specific
to your product.
For general template information, as well as information about the other files that make up model
architecture, see Building Models.
Conventions in Template Descriptions
For each template description, we provide the following:
• Overview - A brief description of the template.
• Template Name - The file name containing the template.
• Major Role - The major role of the template.
• Application - The types of analyses in which you can use the template.
• Description - A complete description of the template and its use.
• Limitations - Limitations of the template design that you should be aware of.
• Files Referenced - The property or MNF files that the template uses to define such entities as
bushings, springs, and flexible bodies.
• Topology - How the different entities of the template connect and how forces or torques are
transferred from one entity to another.
• Parameter Variables - The parameter variables that store key information in the template. For
example, in templates, parameter variables often store angles for a suspension or the orientation
of axes.
• Communicators - Communicators used in the template.
• Notes - Miscellaneous information about the template.
When we refer to communicator and parameter names, we often use the notation [lr] to indicate that there
is both a left and right communicator or parameter of the specified name.
About Designing Templates
Adams/Car templates are parameterized models in which you define the topology of vehicle
components. Building a template means defining parts, how they connect to each other, and how the
template communicates information to other templates and the test rig.
At the template level, it is not crucial that you correctly define the parts, assign force characteristics, and
assign mass properties, because you can modify these values at the subsystem level. It is very important,
however, to correctly define part connectivity and exchange of information, because you cannot modify
them at the subsystem level.
135Working with Templates
When building templates, keep in mind the assembly process. That is, make sure that your templates can
communicate to each other and can communicate to the test rigs you specify. In Adams/Car,
communicators define how models communicate.
Template Updates
The 2005 Driving Machine employs vehicle controllers developed by MSC.Software, commonly known
as Machine Control, which replaces DriverLite functionality, and Adams/SmartDriver. You must update
Adams/Car 2003 powertrain and body templates to make the compatible with the enhanced Driving
Machine in Adams/Car.
To better control speed and path, the 2005 Driving Machine needs additional information about the
vehicle. In particular, the speed controller uses a feed-forward function to ensure quick and accurate
response. However, this requires information about the available engine brake torque, engine drive
torque, brake torque, and aerodynamic drag. You supply this information by creating new output
communicators in your templates powertrain and body/aerodynamic templates. In addition, you must
also enter vehicle parameter data, such as overall steering ratio that is stored in the assembly file.
Powertrain Template Update
You should update powertrain templates by creating new output communicators to match the following
input communicators in the testrig used by the Driving Machine:
• testrig.cis_max_engine_driving_torque
• testrig.cis_max_engine_braking_torque
• testrig.cis_engine_speed
• testrig.cis_engine_map
Maximum engine driving and braking torques
For closed-loop machine control, the maximum engine driving and braking torques must be
communicated to the Driving Machine. The machine control uses these values in its feed forward
computations when determining the needed throttle and brake inputs to achieve a target longitudinal
acceleration. The Driving Machine expects powertrain templates to provide these torques as Solver
Variables. The torques should depend on the engine speed. You must add two output communicators to
your powertrain template and the corresponding entities that are output. The entities are data element
solver variables that compute the maximum driving and maximum braking torques the powertrain
subsystem produces at the current engine speed. Note that without this information machine control of
the vehicle speed and/or longitudinal acceleration will be unreliable.
In the powertrain.tpl and .powertrain_lt.tpl template files distributed in the shared car database, there are
Adams/Solver VARIABLEs with functions computing the maximum powertrain torque (fully open
throttle) and maximum powertrain brake torque (closed throttle):
AKISPL(MAX(0,VARVAL(engine_speed)/ucf_angle_to_radians),1,gss_engine_torque)
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AKISPL(MAX(0,VARVAL(engine_speed)/ucf_angle_to_radians),0,gss_engine_torque)
These functions interpolate the 3D engine map spline at the current engine speed for at full throttle (max
engine driving torque) and closed (0) throttle position (max engine braking torque).
The output communicators you create to output these Adams/Solver VARIABLE are:
Name: engine_driving_torque
Matching Name: engine_maximum_driving_torque
Entity Type: solver_variable
Minor Role: inherit
Entity: engine_driving_torque
Name: engine_braking_torque
Matching Name: engine_maximum_braking_torque
Entity Type: solver_variable
Minor Role: inherit
Entity: engine_braking_torque
Engine Map
If your powertrain contains an engine map spline (torque vs. engine speed and throttle position), you can
output the spline to the Driving Machine via an output communicator to achieve better control of speed
and longitudinal acceleration. However, the engine map is optional. Define the engine_map output
communicator as:
Name: engine_map
Matching Name: engine_map
Entity Type: spline
Minor Role: inherit
Entity: gss_engine_torque
In the templates powertrain.tpl and powertrain_lt.tpl distributed in the shared car database, the
engine_map output communicators reference the gss_engine_torque spline entity. In your own templates,
choose the appropriate spline.
The engine speed is a solver variable outputting the engine speed in radians/s.
Engine speed
In the case of a closed-loop controller on the vehicle forward velocity, you must define an output
communicator in your powertrain template, as follows:
Name: engine_speed
Matching Name: engine_speed
137Working with Templates
Entity Type: solver_variable
Minor Role: inherit
Entity: engine_speed
The solver variable, engine_speed, represents the engine rotational velocity expressed in angular/time
units [rad/second]. In the powertrain template distributed in the shared car database , engine_speed is
defined as MAX(0,DIF(._powertrain.engine_omega)).
The __mdi_sdi_testrig references the output communicator you define and SmartDriver uses that
communicator in the smart_driver_controller_inputs_array. The SmartDriver controller input array
references various entities used to sense certain vehicle states. Adding the engine_speed communicator
enables the longitudinal controller so you can perform a constant-speed maneuver or any other type of
closed-loop machine control.
Aero Drag Force
If your vehicle model includes aerodynamic forces, then the drag force affects the longitudinal dynamics
of the vehicle. The feed-forward speed controller can account for the drag force when predicting the
throttle position needed to follow velocity or acceleration profile, if you create an output communicator
that passes the aerodynamic drag force to the __mdi_sdi_testrig. If your vehicle model does not include
aerodynamic forces, then you do not need to create an output communicator for the drag force.
The chassis template delivered in the shared car database, for example, has an aerodynamic force
modeled using a GFORCE. The GFORCE’s drag (longitudinal) force component is measured in a solver
VARIABLE named aero_drag_force with this function expression:
GFORCE(aero_forces,0,4,aero_drag_reference_marker)
Then, the aerodynamic drag is output to the __mdi_sdi_testrig using output communicator of type solver
variable:
Name: aero_drag_force
Matching Name: aero_drag_force
Entity Type: solver_variable
Minor Role: inherit
Entity: aero_drag_force
Other Vehicle Parameters
Some sets of quantities that are used by the Adams/SmartDriver lateral and longitudinal controllers
cannot be easily inferred from the vehicle model. These quantities are defined in the test rig as parameter
variables and are easily accessible. To modify vehicle parameters, display the Set Full-Vehicle
Parameters dialog. From the Simulate menu, point to Full Vehicle Analysis, and then select Set Full-
Vehicle Parameters.
In the resulting dialog box, you can set the following ratios that affect the lateral dynamics of the vehicle,
providing Adams/SmartDriver information about the characteristics of the steering system. Bad values
Adams/Car
138
almost certainly guarantee solver failure in closed-loop events or, if successful, the vehicle will most
certainly be off course.
• Steering Ratio - Dimensionless ratio between the steering wheel angle and the road wheel
angle. You can obtain this value by running a steering analysis on the front suspension and
steering assembly.
• Steering Rack Ratio - Ratio (angle/length) between the steering hand wheel and the rack
displacement expressed in S.I. units. This parameter influences the response of the controller
only when driving by force/displacement.
The following parameters help Adams/SmartDriver in predicting and calculating the brake signal:
• Max. Front/Rear Brake Torque - Maximum torque, expressed in model units, representing the
torque generated for each front/rear brake in condition of maximum brake demand, also
expressed in model units.
• Brake Bias - Front to rear dimensionless ratio. It can be computed as max_front_brake_torque /
(max_front_brake_torque + max_rear_brake_torque).
These parameters are saved to the assembly file, as well as to the test rig in session.
Creating Topology for Your Templates
Topology in Adams/Car consists of creating elements, such as hardpoints, parts, attachments, and
parameters that define subsystems, as explained next:
• Creating hardpoints - You first create hardpoints. Hardpoints are the Adams/Car elements that
define all key locations in your model. They are the most elementary building blocks that you
can use to parameterize locations and orientations for higher-level entities. Hardpoint locations
define most parts and attachments. Hardpoints are only defined by their coordinate locations.
• Creating parts - Once you’ve defined hardpoints, you create parts and define them using the
hardpoints that you created. In this tutorial, you create two types of parts: general parts, such as
control arm and wheel carrier, and mount parts.
• Creating attachments - Finally, you create the attachments, such as joints and bushings, and
parameters which tell Adams/Car how the parts react in relation to one another. You can define
attachments for the compliant and kinematic analysis modes. The compliant mode uses
bushings, while the kinematic mode uses joints.
Before you begin to build a template, you must decide what elements are most appropriate for your
model. You must also decide which geometries seem most applicable to each part or whether you want
any geometry at all. Once you’ve decided, you create a template and create the basic topology for it.
139Working with Templates
Working with Communicators
You use communicators to exchange of information between subsystems, templates, and the test rig in
your assembly.
This topic includes information for Adams/Car communicators. For general information on
communicators, see the Build tab.
Learn more about working with communicators in Adams/Car:
• Communicators in the Suspension Test Rig
• Communicators in the SDI Test Rig
• Matching Communicators with Test Rigs
Communicators in the Suspension Test Rig
The following tables describe the input and output communicators in the suspension test rig
(.__MDI_SUSPENSION_TESTRIG). In the tables, the notation:
• [lr] indicates that there is both a left and right communicator of the specified name, as in
ci[lr]_camber_angle.
• s indicates a single communicator, as in cis_steering_rack_joint.
Communicators in the Suspension Test Rig
The communicator:Belongs to the
class:
From minor role: Receives:
ci[lr]_camber_angle parameter_real any Camber angle value from the suspension
subsystem. Sets the correct orientation of
the test rig wheels.
ci[lr]_diff_tripot location any Location of the differential.
ci[lr]_toe_angle parameter_real any Toe angle value from the suspension
subsystem. Sets the correct orientation of
the test rig wheels.
ci[lr]_suspension_mount mount any Part to which the test rig wheels can attach.
ci[lr]_suspension_upright mount any Upright part from suspension subsystem.
ci[lr]_jack_frame mount any Not matched (fixed to ground).
ci[lr]_wheel_center location any Location of the wheel center from the
suspension subsystem. Test rig wheels
attach to the suspension at that location.
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Output Communicators in Suspension Test Rig
Communicators in the SDI Test Rig
The following tables describe the input and output communicators in the SDI test rig
(.__MDI_SDI_TESTRIG). In the tables, the notation [lr] indicates that there is both a left and right
communicator of the specified name.
Input Communicators in SDI Test Rig
cis_driveline_active parameter_integer any Integer value stored in the suspension
template/subsystem that indicates the
activity of the drivetrain.
cis_powertrain_to_body mount any Part to which differential outputs are
constrained.
cis_leaf_adjustment_steps parameter_integer any Integer value stored in the leaf spring
template (currently not available).
cis_steering_rack_joint joint_for_motion any Steering-rack translational joint from the
steering subsystem.
cis_steering_wheel_joint joint_for_motion any Steering-wheel revolute joint from the
steering subsystem.
cis_suspension_parameters_ARRAY array any Array used in the suspension characteristic
calculations; comes from the suspension
subsystems.
The communicator:Belongs to the
class:
From minor role: Receives:
The communicator:Belongs to the class:
From minor role: Outputs:
cos_leaf_adjustment_multiplier array any Leaf Spring toolkit. It is currently not supported in
the standard product.
cos_characteristics_input_ARRAY array any Suspension, vehicle, and test-rig parameters array
IDs used by suspension characteristics
calculations routines.
co[l,r]_tripot_to_differential mount any Outputs the ge[lr]_diff_output parts.
cos_tire_forces_array_left array any Outputs array of Adams IDs used by the
conceptual suspension module.
cos_tire_forces_array_right array any Outputs array of Adams IDs used by the
conceptual suspension module.
141Working with Templates
The communicator:Belongs to the
class:
From minor role: Receives:
cis_body_subsystem mount inherit Output from the body subsystem. It indicates
the part that represents the body.
cis_chassis_path_reference marker any Marker from the body subsystem. It is used to
measure path, roll, and sideslip error in a
constant radius cornering maneuver.
cis_driver_reference marker any Marker from the body subsystem. It is used in
Adams/Driver simulations.
cis_engine_rpm solver_variable any Adams/Solver variable for engine revolute
speed, in rotations per minute, from the
powertrain subsystem.
cis_engine_speed solver_variable any Adams/Solver variable for engine revolute
speed, in radians per second, from the
powertrain subsystem.
cis_measure_for_distance marker any Marker used to measure the distance traveled
in the forward direction of the vehicle, from
the body subsystem.
cis_diff_ratio parameter_real any Real parameter variable for final drive ratio,
from the powertrain subsystem.
cis_steering_rack_joint joint_for_motion front Steering-rack translational joint from the
steering subsystem.
cis_steering_wheel_joint joint_for_motion front Steering-wheel revolute joint from the
steering subsystem.
cis_max_brake_value parameter_real any Output from brake subsystem (maximum
brake signal value).
cis_max_engine_speed parameter_real any Output from powertrain subsystem (maximum
engine rpm value).
cis_max_gears parameter_intege
r
any Output from powertrain (maximum number of
allowed gears).
cis_max_rack_displacement parameter_real any Output displacement limits from steering
subsystem. Used by the Standard Driver
Interface.
cis_max_rack_force parameter_real any Output force limits from steering subsystem.
Used by the Standard Driver Interface.
cis_max_steering_angle parameter_real any Output angle limits from steering subsystem.
Used by the Standard Driver Interface.
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Output Communicators in SDI Test Rig
cis_max_steering_torque parameter_real any Output from steering subsystem.
cis_max_throttle parameter_real any Output from powertrain (maximum value of
throttle signal).
cis_min_engine_speed parameter_real any Output from powertrain subsystem (minimum
engine rpm value, used for shifting strategy).
cis_rotation_diff diff any Output from powertrain (it is a differential
equation used to measure crankshaft
acceleration; its integral is used for engine
rpm).
cis_transmission_spline spline any Spline for transmission gears (output from
powertrain: reduction ratios for every gear).
cis_transmission_input_omega solver_variable any The transmission input engine variable from
the powertrain template.
cis_clutch_diff diff any Clutch slip differential equation from the
powertrain template.
cis_clutch_displacement_ic solver_variable any The clutch initial displacement (engine
crankshaft torque at static equilibrium) from
the powertrain template.
ci[lr]_front_suspension_mount mount front The hub parts (wheel carriers) from
suspension templates (front and rear)
ci[lr]_rear_suspension_mount mount rear The hub parts (wheel carriers) from
suspension templates (front and rear)
The communicator:Belongs to the
class:
From minor role: Receives:
The communicator:Belongs to the
class:
From minor role: Outputs:
cos_brake_demand solver_variable any Brake demand to the brake subsystem.
cos_clutch_demand solver_variable any Clutch demand to the powertrain subsystem.
cos_desired_velocity solver_variable any Desired velocity Adams/Solver variable. Other
subsystems can reference it.
cos_initial_engine_rpm parameter_real any Initial engine RPM real variable to the powertrain
subsystem.
cos_throttle_demand solver_variable any Throttle demand to the powertrain subsystem.
143Working with Templates
Matching Communicators with Test Rigs
When you create a template, you must meet the following conditions to ensure that an analysis will work
with your new template:
• The template must be compatible with other templates and with the test rigs, for example, the
.__MDI_SUSPENSION_TESTRIG. The template must also contain the proper output
communicators.
• If the template is a suspension template (for example, its major role is suspension), the template
must contain a suspension parameters array. The suspension parameters array identifies to the
suspension analysis how the steer axis should be calculated and whether the suspension is
independent or dependent.
For example, for a suspension template to be compatible with the suspension test rig, the suspension
template must contain either the mount or the upright output communicators. In the following table, the
notation [lr] indicates that there is both a left and right communicator of the specified name.
Output Communicators in Suspension Templates
The co[lr]_suspension_mount output communicators publish the parts to which the test rig wheels
should mount. As you create these communicators, ensure that you set their minor role to inherit. By
setting the minor role to inherit, the communicator takes its minor role from the minor role of the
subsystems that use your suspension template.
cos_transmission_demand solver_variable any Transmission (gear) demand to the powertrain
subsystem.
cos_sse_diff1 diff any Differential equation computed during quasi-
static prephase, used to control the vehicle
longitudinal dynamics.
cos_std_tire_ref location any X,Y,Z location of standard tire reference marker
(positioned appropriately at the correct height,
including 2% of road penetration).
The communicator:Belongs to the
class:
From minor role: Outputs:
The communicator: Belongs to the class: From minor role: Receives:
co[lr]_suspension_mount mount inherit suspension_mount
co[lr]_suspension_upright mount inherit suspension_upright
co[lr]_wheel_center location inherit wheel_center
co[lr]_toe_angle parameter_real inherit toe_angle
co[lr]_camber_angle parameter_real inherit camber_angle
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144
The co[lr]_wheel_center output communicators publish the location of the wheel centers to the test rig
so the test rig can locate itself relative to the suspension. As you create these types of communicators,
make sure that you also leave their minor role set to inherit.
The toe and camber communicators (co[lr]_toe_angle and co[lr]_camber_angle) publish, to the test rig,
the toe and camber angles set in the suspension so the test rig can orient the wheels correctly.
145Working with Templates
Templates
Conceptual Steering System
Overview
Using conceptual templates, Adams/Car allows you to study system-level vehicle dynamics without
having to create detailed multibody suspension models.
Figure 1 Conceptual Steering System
Template name
_concept_steering
Major role
Steering
Application
Suspension and full-vehicle analyses with the conceptual suspension system template.
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146
Description
The conceptual steering system is a very simple model of steering that communicates the steering-wheel
revolute joint to the conceptual suspension system. The conceptual suspension system uses the rotation
of the joint i and j markers as a measure of the steering input.
Topology
The conceptual steering system template consists of a steering wheel and column rotating through a
revolute joint. The revolute joint connects the rigid bodies to a mount part.
Communicators
Mount parts provide the connectivity from the template to the body subsystems. Output communicators
publish steering limits for displacement, angle, and force, and torque information.
The following table lists the communicators in the template.
Conceptual Suspension System
Overview
Using conceptual templates, Adams/Car allows you to study system-level vehicle dynamics without
having to create detailed multibody suspension models. You can use the conceptual suspension system
to define the wheel movements with respect to the body using a collection of characteristic curves or
dependencies.
The communicator: Belongs to the class: Has the role:
cos_max_steering_angle parameter_real inherit
cos_max_steering_torque parameter_real inherit
cos_steering_wheel_joint joint_for_motion inherit
cis_steering_column_to_ body mount inherit
147Working with Templates
Figure 2 Conceptual Suspension System
Template name
_concept_suspension
Major role
Suspension
Application
Suspension or full-vehicle analyses. You can mix and match conceptual suspensions in a full-vehicle
assembly with multibody suspension models.
Default files referenced
References the file dwb_front.scf, stored in the suspension_curves.tbl directory in the Adams/Car shared
database. The suspension characteristic file defines kinematic relations or dependencies between
suspension characteristic angles, suspension track, and base and the vertical wheel and steer travel.
Topology
The topology of the template is very simple, and you do not need to modify it in the Template Builder.
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Three curve-to-curve constraints drive each wheel carrier along a predefined trajectory. A user-written
curve subroutine calculates the trajectory depending on the inputs to the system, such as the forces and
torques coming from the tire subsystem and the amount of wheel and steer travel.
A conceptual suspension will have four degrees of freedom. A conceptual vehicle, therefore, will have
14 degrees of freedom. The following table lists the model topology for the left side of the template. The
right side entities are connected in a similar way.
Parameters
The toe and camber parameter values define the wheel spin axis, and the unsprung mass parameter
variable defines the wheel carrier part mass. Finally, 68 hidden variables define the dependency flags
array, with each of parameters setting the status (active or inactive) of a dependency.
Communicators
Mount parts provide connectivity from the template to the body subsystems and differential. Input
communicators receive information about the tire forces, the steer axis, and the steering-wheel joint.
Output communicators publish toe, camber, steer axis, and wheel center location information.
The following table lists the communicators in the template.
The joint: Connects the part: To the part:
left_ptcv_O (point-to-curve) wheel_carrier_left mts_body
left_ptcv_X (point-to-curve) dummy_left_X mts_body
jolrev_spindle_upright hub_left wheel_carrier_left
joltra_tripot_to_differential gel_tripot mtl_tripot_to_differential
jolcon_drive_sft_int_jt gel_tripot gel_drive_shaft
jolcon_drive_sft_otr gel_drive_shaft hub_left
jolinp_dummy_wheelplane_y dummy_left_X wheel_carrier_left
jolinp_dummy_wheelplane_z dummy_left_X wheel_carrier_left
jolori_dummy_wheelplane_ori dummy_left_X wheel_carrier_left
josfix_subframe_to_body ges_subframe mts_body
The communicator: Belongs to the class: Has the role:
ci[lr]_ARB_pickup location inherit
ci[lr]_tripot_to_differential mount inherit
cis_body mount inherit
cis_characteristics_input_ARRAY array inherit
cis_steering_wheel_joint joint_for_motion inherit
149Working with Templates
Disc-Brake System
Overview
The disc-brake system template represents a device that applies resistance to the motion of a vehicle.
cis_tire_forces_array_left array inherit
cis_tire_forces_array_right array inherit
co[lr]_camber_angle parameter_real inherit
co[lr]_suspension_mount mount inherit
co[lr]_suspension_upright mount inherit
co[lr]_toe_angle parameter_real inherit
co[lr]_tripot_to_differential location inherit
co[lr]_wheel_center location inherit
cos_driveline_active parameter_integer inherit
cos_engine_to_subframe mount inherit
cos_suspension_parameters_ARRAY array inherit
The communicator: Belongs to the class: Has the role:
Notes: Spring and damper entities in the conceptual suspension template consist of a special user-
defined element. A user-written subroutine computes the forces. The subroutine takes into
account the nonlinear spring/damper characteristics and the stabilizer bar forces
You must use the conceptual suspension system template with the Conceptual Steering
System.
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Figure 3 Disc-Brake System
Template name
_brake_system_4Wdisk
Major role
Brake.
Application
Full-vehicle analysis to simulate the effect of braking on the dynamics of the vehicle.
Description
The disc-brake system template represents a simple model of a brake system. It applies a rotational torque
between the caliper and the rotor.
Files referenced
None.
Topology
The caliper part is mounted to the suspension upright, while the rotor is mounted to the wheel. A
rotational SFORCE is applied between the two parts.
151Working with Templates
Parameters
The toe and camber values that the suspension subsystem publishes define the spin axis orientation. In
addition, the braking torque is expressed as a function of a number of parameters.
The following table lists the parameters in the template.
Limitations
The disc-brake template is a simple model of a brake system. It does not model the complex interaction
between the rotor and caliper.
Communicators
Mount parts provide the connectivity between the template and suspension subsystems. Input
communicators receive information about the toe and camber suspension orientation and the wheel-
center location. Input to the brake system is brake demand.
The following table lists the communicators in the template.
The parameter: Takes the value: Its units are:
front_brake_bias Real No units
front_brake_mu Real No units
front_effective_piston_radius Real mm
front_piston_area Real mm2
front_rotor_hub_wheel_offset Real mm
front_rotor_hub_width Real mm
front_rotor_width Real mm
max_brake_value Real No units
rear_brake_mu Real No units
rear_effective_piston_radius Real mm
rear_piston_area Real mm2
rear_rotor_hub_wheel_offset Real mm
rear_rotor_hub_width Real mm
rear_rotor_width Real mm
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The communicator: Belongs to the class: Has the role:
ci[lr]_front_camber_angle parameter_real front
ci[lr]_front_rotor_to_wheel mount front
ci[lr]_front_toe_angle parameter_real front
ci[lr]_front_wheel_center location front
ci[lr]_front_suspension_ upright mount front
ci[lr]_rear_rotor_ro_wheel mount rear
ci[lr]_rear_suspension_ upright mount rear
ci[lr]_rear_toe_angle parameter_real rear
ci[lr]_rear_camber_angle parameter_real rear
ci[lr]_rear_wheel_center location rear
cis_brake_demand solver_variable any
cos_max_brake_value parameter_real inherit
Notes: The torque on the rotor depends on a number of parameters. The front right torque function
is:
T = 2 x PistonArea x BrakeLinePressure x µ x EffectivePistonRadius x STEP
where:
• BrakeLinePressure is calculated as follows:
BrakeLinePressure = BrakeBias * BrakeDemand * 0.1
where:
• BrakeBias defines the front and rear proportioning of the brake line pressure.
Note that although the term is constant, in reality, simple hydraulic systems
allow dynamic front and rear proportioning of the brake pressure depending on
a number of factors, including longitudinal slip angle of the tires and dynamic
load transfer.
• BrakeDemand is the force on the pedal (N) as it is output from the analysis.
• 0.1 is a conversion factor that converts into pressure the force applied on the
pedal.
• STEP is the function of the rotation of the rotor to wheel and suspension upright
markers. The function prevents backward spinning of the wheels. STEP is a
simple function that measures the WZ rotation of the marker on the rotor with
respect to the marker on the upright and reverses the sign of the applied torque
if the wheel is spinning backward.
153Working with Templates
Double-Wishbone Suspension
Overview
A double-wishbone suspension is one of the most common suspension designs. It uses two lateral control
arms to hold the wheel carrier and control its movements.
Figure 4 Double-Wishbone Suspension
Template name
_double_wishbone
Major role
Suspension
Application
Suspension and full-vehicle assemblies
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Description
The double-wishbone template represents the most common design for doublewishbone suspensions.
You can use the template as a front steerable suspension or as a rear non-steerable suspension.
You can set subsystems based on this template to kinematic or compliant mode. In kinematic mode,
Adams/Car replaces the bushings that connect the control arms to the body mount part with a
corresponding purely kinematic constraint. Adams/Car also does this for the top mount and lower strut
mount.
You can deactivate the subframe part, as well as the halfshafts. A spring acts between the upper mount
part and the lower strut. A bumpstop acts between the upper and lower strut parts.
Files referenced
Bushings, springs, dampers, and bumpstops property files
Topology
The lower wishbone connects to a subframe or to the mount if you've deactivated the subframe. The
upper wishbone connects to the body mount part. A spherical joint constrains the upright part to the upper
and lower arms.
A spherical joint also connects the tie rods to the uprights. Tie rods attach to mount parts through convel
joints. Convel joints also connect the tripots to the drive shafts. A static rotation control actuator locks
the rotational degree of freedom of the hub during quasi-static analyses.
The joint: Connects the part: To the part:
jklrev_lca gel_lower_control_arm ges_subframe
jolsph_lca_balljoint gel_upright gel_lower_control_arm
jolsph_tierod_outer gel_tierod gel_upright
jolcon_tierod_inner gel_tierod mtl_tierod_to_steering
josfix_subframe_rigid ges_subframe mts_subframe_to_body
jklhoo_top_mount_kinematic gel_upper_strut mtl_strut_to_body
jolsph_uca_balljoint gel_upper_control_arm gel_upright
jolcyl_lwr_upr_strut gel_lower_strut gel_upper_strut
jklrev_uca gel_upper_control_arm mtl_uca_to_body
jklhoo_lwr_strut_kinematic gel_lower_strut gel_lower_control_arm
joltra_tripot_to_differential gel_tripot mtl_tripot_to_differential
jolcon_drive_sft_int_jt gel_tripot gel_drive_shaft
jolcon_drive_sft_otr gel_drive_shaft gel_spindle
155Working with Templates
Parameters
Toe and camber variables define wheel spin axis, spindle part, and spindle geometry. The following table
lists the parameters in the template.
Communicators
Mount parts provide connectivity from the template to body subsystems and the differential. Output
communicators publish toe, camber, steer axis, and wheel-center location information to the appropriate
subsystems and the test rig. The following table lists the input and output communicators.
The parameter: Takes the value: Its units are:
phs_driveline_active Integer No units
phs_kinematic_flag Integer No units
pvs_subframe_active Integer No units
pv[lr]_toe_angle Real Degrees
pv[lr]_camber_angle Real Degrees
pv[lr]_drive_shaft_offset Real mm
The communicator: Belongs to the class: Has the role:
ci[lr]_ARB_pickup location inherit
ci[lr]_strut_to_body mount inherit
ci[lr]_tierod_to_steering mount inherit
ci[lr]_tripot_to_differential mount inherit
ci[lr]_uca_to_body mount inherit
cis_subframe_to_body mount inherit
co[lr]_arb_bushing_mount mount inherit
co[lr]_camber_angle parameter_real inherit
co[lr]_droplink_to_ suspension mount inherit
co[lr]_suspension_mount mount inherit
co[lr]_suspension_upright mount inherit
co[lr]_toe_angle parameter_real inherit
co[lr]_tripot_to_differential location inherit
co[lr]_wheel_center location inherit
cos_driveline_active parameter_integer inherit
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156
Flexible LCA Double-Wishbone Suspension
Overview
The flexible LCA double-wishbone suspension template is similar to the standard Double-Wishbone
Suspension. In the flexible template, however, a flexible representation replaces the rigid body lower
control arms.
Figure 5 Flexible LCA Double-Wishbone Suspension
cos_engine_to_subframe mount inherit
cos_rack_housing_to_suspension_subframe mount inherit
cos_suspension_parameters_ARRAY array inherit
The communicator: Belongs to the class: Has the role:
Note: The integer parameter variables allow you to activate and deactivate the subframe part and
the driveshafts. The kinematic flag variable toggles between kinematic and compliant
mode.
157Working with Templates
Template name
_double_wishbone_flex
Major role
Suspension
Application
Suspension and full-vehicle assemblies
Description
Flexible bodies replace the left and right rigid lower control arms.
MNF files referenced
LCA_left_shl.mnf and LCA_right_shl.mnf. In addition, because of the way the node IDs are numbered,
you can swap the default modal neutral files with LCA_left_tra.mnf and LCA_right_tra.mnf.
Topology
In addition to the general topology described for the Double-Wishbone Suspension, this template uses
interface parts to connect the flexible bodies to the rest of the suspension. Node IDs define the location
of interface parts.
Parameters
Refer to the Double-Wishbone Suspension.
Communicators
Refer to the Double-Wishbone Suspension.
ISO Road Course
Overview
The ISO road course template represents a closed circuit with an ISO lane-change section.
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158
Figure 6 ISO Road Course
Template name
_ISO_road_course
Major role
Environment
Application
With the optional Adams/Driver module
Description
The ISO road course template consists of shell elements and frustums, and represents a closed circuit
with an ISO lane-change section.
Files referenced
Geometry elements (shells) reference shell files stored in the Adams/Car shared database in the
shell_graphics.tbl directory. The shell files are Iso_road_inr.shl, Iso_road_otr.shl, and Iso_road_c.shl.
Topology
All the graphic elements are created on the ground part.
159Working with Templates
Parameters
Contains no parametric information.
Communicators
Contains no communicators.
MacPherson Suspension
Overview
The MacPherson suspension design in this template is similar to the SLA geometry, and is probably the
most often used suspension for passenger cars in the world. It uses a telescopic strut incorporating a
damper element. The upper end is fixed to the body and the lower end is located by linkages. The
MacPherson design provides advantages in packaging, and it is generally used for front-wheel-drive
cars.
Note: The corresponding Adams/Driver representation of this course is available as a trace on the
x-y plane and lane width in the driver_roads.tbl directory. The file is called
ISO_road_course.drd. You can use the file to run full-vehicle analyses with Adams/Driver.
Including the ISO road course template in your full-vehicle assembly adds a graphical
representation of the circuit.
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160
Figure 7 MacPherson Suspension
Template name
_macpherson
Major role
Suspension
Application
Suspension and full-vehicle assemblies
Description
The MacPherson suspension template represents the most common design for MacPherson suspensions.
You can use the template as a front steerable suspension or as a rear non-steerable suspension.
You can set the subsystems based on this template to kinematic or compliant mode. In kinematic mode,
Adams/Car replaces the bushings with the corresponding kinematic constraints. The bushings connect
the control arm and the damper strut to the body mount parts. You can also activate or deactivate
driveshafts.
161Working with Templates
A spring acts between the upper strut part and the lower strut. Bumpstops and reboundstops are also
present.
Files referenced
Bushings, springs, dampers, bumpstops, and reboundstops property files
Topology
The MacPherson suspension template represents a standard design employing a one-piece lower control
arm (also known as A-arm) and a subframe. The upright to which the wheel mounts is located by the
lower control arm, the tie rod, and the strut. The lower control arm regulates the fore-aft and lateral
motions of the upright. The tie rod controls steering rotation of the upright, and the strut controls the
vertical motion of the upright and the side and front view rotations, as well. A static rotation control
actuator locks the rotational degree of freedom of the hub during quasi-static analyses.
The following table lists the topological information of the left side of the MacPherson suspension.
Parameters
Toe and camber variables in the template define the wheel spin axis, spindle part, and spindle geometry.
The following table lists the parameters in the templates.
The joint: Connects the part: To the part:
jklrev_lca gel_lower_control_arm ges_subframe
jolsph_lca_balljoint gel_upright gel_lower_control_arm
jolcyl_strut gel_upright gel_upper_strut
jolsph_tierod_outer gel_tierod gel_upright
jolcon_tierod_inner gel_tierod mtl_tierod_to_steering
jksfix_subframe_rigid ges_subframe mts_subframe_to_body
jklhoo_top_mount_kinematic gel_upper_strut mtl_strut_to_body
joltra_tripot_to_differential gel_tripot mtl_tripot_to_differential
jolcon_drive_sft_int_jt gel_tripot gel_drive_shaft
jolcon_drive_sft_otr gel_drive_shaft gel_spindle
jolrev_spindle_upright gel_spindle gel_upright
The parameter: Takes the value: Its units are:
phs_driveline_active Integer No units
phs_kinematic_flag Integer No units
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162
Communicators
Mount parts provide the connectivity from the template to the body subsystems and differential. Output
communicators publish toe, camber, steer axis, and wheel-center location information to the appropriate
subsystems and test rig. The following table lists the input and output communicators in the template.
pv[lr]_toe_angle Real Degrees
pv[lr]_camber_angle Real Degrees
pv[lr]_drive_shaft_offset Real mm
The communicator: Belongs to the class: Has the role:
ci[lr]_ARB_pickup location inherit
ci[lr]_strut_to_body mount inherit
ci[lr]_tierod_to_steering mount inherit
ci[lr]_tripot_to_differential mount inherit
cis_subframe_to_body mount inherit
co[lr]_arb_bushing_mount mount inherit
co[lr]_camber_angle parameter_real inherit
co[lr]_droplink_to_ suspension mount inherit
co[lr]_suspension_mount mount inherit
co[lr]_suspension_upright mount inherit
co[lr]_toe_angle parameter_real inherit
co[lr]_tripot_to_differential location inherit
co[lr]_wheel_center location inherit
cos_driveline_active parameter_integer inherit
cos_rack_housing_to_ suspension_subframe mount inherit
cos_suspension_parameters_ARRAY array inherit
The parameter: Takes the value: Its units are:
Note: The integer parameter variables let you activate and deactivate the driveshafts. The
kinematic flag variable toggles between kinematic and compliant mode replacing the joints
with the corresponding elastic elements. For example, Adams/Car replaces the revolute
joints that connect the lower control arms to the subframe with bushings
163Working with Templates
Multi-Link Suspension
Overview
The multi-link suspension represents an independent suspension model for use as a rear suspension.
Figure 8 Multi-Link Suspension
Template name
_multi_link
Major role
Suspension
Application
Suspension and full-vehicle assemblies
Description
The multi-link suspension template represents a common rear independent suspension design. It includes
a subframe (represented by the outline graphics) that is connected to the upper arm, to the lateral links,
and to the track rod. The suspension is nonsteerable and intended to be used as a rear suspension only.
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164
Files referenced
Springs, dampers, and bushings property files
Topology
Spherical joints, which are active in kinematic mode, connect the uprights to links. Bushings connect the
trailing links to the mount parts. Springs and dampers act between the trailing links and the body. A static
rotation control actuator locks the rotational degree of freedom of the hub during quasi-static analyses.
The following table provides a topological map of the template.
Parameters
Toe and camber variables in the template define the wheel spin axis, spindle part, and spindle geometry.
The following table lists the parameters in the templates.
The joint: Connects the part: To the part:
jklsph_hub_tl gel_Upright gel_Trailing_Link
jklhoo_trailing_link_body gel_Trailing_Link mtl_trailing_link_body
jklrev_ula_sbf gel_upper ges_Subframe
joltra_dpr_upr_dpr_lwr gel_Damper_Upper gel_Damper_Lower
jklsph_dpr_lwr_tl gel_Damper_Lower gel_Trailing_Link
jklhoo_dpr_spring_seat_upper gel_Damper_Upper mtl_Spring_Seat_Upper
jksfix_sbf_body ges_Subframe mtl_body_sbf_front
jklsph_hub_ll gel_Upright gel_lateral
jklsph_hub_tr gel_Upright gel_Track_Rod
jklhoo_sbf_ll ges_Subframe gel_lateral
jklhoo_sbf_tr ges_Subframe gel_Track_Rod
jklsph_hub_ula gel_Upright gel_upper
joltra_tripot_to_differential gel_tripot mtl_tripot_to_differential
jolcon_drive_sft_int_jt gel_tripot gel_drive_shaft
jolcon_drive_sft_otr gel_drive_shaft gel_spindle
jolrev_spindle_upright gel_spindle gel_Upright
The parameter: Takes the value: Its units are:
phs_driveline_active Integer No units
phs_kinematic_flag Integer No units
pvs_subframe_active Integer No units
165Working with Templates
Communicators
The following table lists the communicators in the template.
Parallel-Link Steering System
Overview
The parallel-link steering system template is essentially a four-bar mechanism consisting of a pitman
arm, center link, and idler arm.
pv[lr]_toe_angle Real Degrees
pv[lr]_camber_angle Real mm
pv[lr]_drive_shaft_offset Real mm
The communicator: Belongs to the class: Has the role:
ci[lr]_body_sbf_front mount inherit
ci[lr]_body_sbf_rear mount inherit
ci[lr]_Spring_Seat_Upper mount inherit
ci[lr]_trailing_link_body mount inherit
ci[lr]_tripot_to_differential mount inherit
co[lr]_camber_angle parameter_real inherit
co[lr]_suspension_mount mount inherit
co[lr]_suspension_upright mount inherit
co[lr]_tripot_to_differential location inherit
co[lr]_wheel_center location inherit
cos_driveline_active parameter_integer inherit
cos_suspension_ parameters_ARRAY array inherit
The parameter: Takes the value: Its units are:
Note: The integer parameter variables let you activate and deactivate the subframe part and the
driveshafts. The kinematic flag variable toggles between kinematic and compliant mode.
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166
Figure 9 Parallel-Link Steering
Template name
_parallel_link_steering
Major role
Steering
Application
Suspension and full-vehicle assemblies
Description
A recirculating ball steering gear transmits motion from the steering wheel to the pitman arm. The pitman
arm rotates to impart motion to the center link and idler arm. The translation of the center link pulls and
pushes the tie rods to steer the wheels.
Files referenced
Steering assist and torsion bar deflection property file. The default property file is mdi_steer_assis.ste,
stored in the steer_assist.tbl directory of the shared Adams/Car database.
167Working with Templates
Topology
The recirculating ball steering gear consists of three major parts:
• Ball screw
• Rack
• Sector
The steering wheel rotates the steering input shaft. A torsion bar attaches the steering input shaft to a ball
screw. The ball screw imparts translational motion to the steering gear through a coupler. The steering
gear, in turns, rotates the sector through a coupler, which is connected directly to the pitman arm shaft.
The following table maps the topology of the template.
The joint: Connects the part: To the part:
joshoo_column_intermediate ges_steering_column ges_intermediate_shaft
joshoo_intermediate_shaftinput ges_intermediate_shaft ges_input_shaft
josrev_steering_wheel ges_steering_wheel ges_column_housing
joscyl_steering_column ges_steering_column ges_column_housing
josfix_column_housing_to_housing_
mount
ges_column_housing mts_steering_column_to_body
jolsph_centerlink_arm ges_center_link gel_arm
jolrev_pitman_arm_steering_gear gel_arm swl_steering_gear_mount
josrev_ball_screw_steering_gear ges_ball_screw swl_steering_gear_mount
josrev_input_shaft_steering_gear ges_input_shaft swl_steering_gear_mount
jostra_rack_steering_gear ges_rack swl_steering_gear_mount
josfix_steering_gear_housing ges_steering_gear_housing swl_steering_gear_mount
josper_centerlink_pitman_arm ges_center_link gel_arm
vfo_steering_assist ges_rack swl_steering_gear_mount
gksred_ball_screw_input_shaft_lock josrev_ball_screw_steering
_gear
josrev_input_shaft_steering_
gear
grsred_steering_wheel_column_lock josrev_steering_wheel joscyl_steering_column
grsred_ball_screw_rack josrev_ball_screw_steering
_gear
jostra_rack_steering_gear
grsred_pitman_arm_rack jolrev_pitman_arm_steerin
g_gear
jostra_rack_steering_gear
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168
Parameters
A parameter variable switches between kinematic and compliant mode, effectively defining the status of
the ball screw input shaft lock reduction gear.
Communicators
The following table lists the communicators in the template.
Pitman Arm Steering System
Overview
The pitman arm steering system template is a simple steering system derived from a parallel-link design.
It is commonly used in trucks. It consists of a three-bar mechanism: pitman arm, draglink, and tie rod.
The communicator: Belongs to the class: Has the role:
ci[lr]_steering_gear_to_body mount inherit
ci[lr]_steering_gear_to_suspension_subframe mount inherit
cis_steering_column_to_ body mount inherit
co[lr]_tierod_to_steering mount front
cos_steering_rack_joint joint_for_motion inherit
cos_steering_wheel_joint joint_for_motion inherit
Note: The parallel-link steering template contains general spline elements. The general spline
element gss_torsion_bar spline provides torque as a function of the angular deflection of
the input shaft relative to the ball screw. A switch part is also present. It allows you to
explore two different topological solutions. You can rigidly connect the steering gear to the
body or to the suspension_subframe part.
169Working with Templates
Figure 10 Pitman Arm Steering System
Template name
_pitman_arm
Major role
Steering
Application
Suspension and full-vehicle assemblies
Description
A recirculating ball steering gear transmits motion from the steering wheel to the pitman arm. The pitman
arm rotates to impart motion to the draglink. The draglink pulls and pushes the tie rod and steers the
wheels.
Files referenced
The point torque actuator references the torsion_bar datablock in the mdi_steering.ste property file,
stored in the Adams/Car shared database, under the steer_assists.tbl table or directory.
Topology
The recirculating ball steering gear consists of three major parts:
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170
• Ball screw
• Rack
• Sector
The steering wheel rotates the steering input shaft. The steering input shaft attaches to the ball screw
through a torsion bar, currently locked by a coupler. The ball screw imparts translational motion to the
rack, through a coupler. The rack, in turns, rotates the sector through a coupler.
The sector is connected directly to the pitman arm shaft. The pitman arm drags the draglink, which is
directly connected to the right wheel, and pulls the tie rod, connected to the left wheel. Spherical joints
connect the draglink and tie rod.
The following table maps the topology of the template.
The joint: Connects the part: To the part:
joshoo_column_intermediate ges_steering_column ges_intermediate_shaft
joshoo_intermediate_shaft_i
nput
ges_intermediate_shaft ges_input_shaft
josrev_steering_wheel ges_steering_wheel ges_column_housing
joscyl_steering_column ges_steering_column ges_column_housing
josfix_column_housing_to_h
ousing_mount
ges_column_housing mts_steering_column_to_body
josrev_pitman_arm_steering
_gear
mts_steering_gear_to_suspension
_subframe
ges_idle_arm
jossph_centerlink_arm ges_idle_arm ges_draglink
josrev_input_shaft_steering_
gear
ges_input_shaft mts_steering_gear_to_suspension
_subframe
josrev_ball_screw_steering_
gear
ges_ball_screw mts_steering_gear_to_suspension
_subframe
jostra_rack_steering_gear ges_rack mts_steering_gear_to_suspension
_subframe
jossph_draglink_to_tierod ges_draglink ges_tierod
grsred_steering_wheel_colu
mn_lock
josrev_steering_wheel joscyl_steering_column
gksred_ball_screw_input_sh
aft_lock
josrev_ball_screw_steering_gear josrev_input_shaft_steering_gear
grsred_pitman_arm_rack josrev_pitman_arm_steering_gea
r
jostra_rack_steering_gear
grsred_ball_screw_rack josrev_ball_screw_steering_gear jostra_rack_steering_gear
171Working with Templates
Parameters
A parameter variable switches between kinematic and compliant mode, effectively defining the status of
the ball screw input shaft lock reduction gear.
Communicators
The following table lists the communicators in the template.
Powertrain System
Overview
The Adams/Car shared database includes a powertrain template, powertrain.tpl. The template models an
engine, manual transmission, and a limited-slip differential that may be used for a front engine, front-
wheel-drive vehicle, or a rear engine, rear-wheel-drive vehicle.
The communicator: Belongs to the class: Has the role:
ci[lr]_steering_gear_to_suspension_subframe mount inherit
cis_steering_column_to_ body mount inherit
cos_tierod_to_steering mount front
cos_draglink_to_steering joint_for_motion inherit
cos_steering_wheel_joint joint_for_motion inherit
Note: The pitman arm steering system template does not interface with any of the Adams/Car
shared database suspension templates because those suspension templates have tie rods. To
correctly assemble the pitman arm steering to a suspension subsystem, you must remove
the tie rods from the suspension. The draglink and the tie rod have to be mounted to the left
and right upright parts.
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172
Figure 11 Powertrain
Template name
_powertrain
Major role
Powertrain
Application
Full-vehicle assemblies
Description
The powertrain system template represents an engine, clutch, transmission, and differential:
• Engine model - Consists of a single part (ges_engine) representing the total mass and inertia of
the engine block, clutch housing, and transmission. A general spline element
(gss_engine_torque) represents the engine's steady-state torque versus engine speed and throttle
position. Before any analysis, gss_engine_torque is updated by reading the engine torque versus
engine speed and throttle from a powertrain property file. For example,
mdids://acar_shared/powertrains.tbl/V8_240HP_400Nm.pwr.
173Working with Templates
• To allow for larger integration time steps during simulation, the engine crankshaft is not
included as a part in the templates. Instead of a rotating crankshaft part, a differential equation
(engine_omega) integrates the engine crankshaft's rotational acceleration (Adams/Solver
requires one integration time step for each 60 degrees of part rotation). The engine crankshaft's
rotational acceleration is the difference between the engine torque and the clutch torque divided
by the engine rotational inertia.
• Clutch model - The clutch torque is modulated by the clutch demand, which ranges in value
from zero (0) to one (1):
• A clutch demand of zero means that the driver's foot is off the clutch pedal and the clutch is
closed.
• A clutch demand of one means that the driver has pushed the clutch pedal completely to the
floor and the clutch is open.
You can set the values of clutch demand, for which the clutch is completely closed or open,
using the parameter variables pvs_clutch_closed and pvs_clutch_open.
The clutch develops torque only when it is at least partially closed and there is some slip
displacement or slip speed between the engine crankshaft and the transmission input shaft.
When the clutch is closed, it acts like a torsional spring-damper, except that the maximum clutch
torque developed is limited by the clutch capacity, which you can modify (pvs_clutch_capacity).
You also set the clutch's torsional stiffness and damping. When the clutch is partially closed, the
clutch stiffness and damping, as well as the clutch capacity (torque), are scaled by the clutch
demand.
The clutch slip speed is the difference between the engine crankshaft and the transmission input
shaft rotational speeds. When the clutch is closed, the clutch slip displacement is the integral of
the clutch slip speed. When the clutch is open, the clutch slip displacement decays to zero with a
time constant given by pvs_clutch_tau.
• Transmission model - The transmission model is simple: it applies the gear ratio selected by the
gear demand, and has no rotating inertia. The clutch torque is multiplied by the selected gear
ratio and applied to the differential input shaft. The differential input shaft speed is likewise
multiplied by the same ratio to determine the transmission input shaft speed. You can set the
number of gears and the ratio for each gear:
• A gear number of zero (0) represents neutral.
• A gear number of minus one (-1) represents reverse.
• Differential model - The differential model has rotating left and right output shaft parts that
connect to half-shafts in suspension subsystems. The differential input shaft speed is the average
of the left and right output shaft speeds multiplied by the final drive ratio you enter. Likewise,
the transmission output torque is multiplied by the final drive ratio and then split equally
between the two output shafts. A reaction torque is applied about the longitudinal axis to the
ges_engine part.
The differential model includes a limited slip torque that acts between the left and right
differential output shafts. The torque depends on the difference between the output shaft speeds.
The limited slip torque-speed characteristic is read from a property file in the differentials.tbl.
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174
Files referenced
The file, V12_engine_map.pwr, stored in the powertrains.tbl directory, defines the engine map. The
differential references the MDI_viscous.dif property file, stored in the differentials.tbl directory. The
MDI_viscous.dif property file defines the slip torque-speed relationship as a two-dimensional spline.
Topology
The powertrain template contains very simple topological information because it is a functional
representation of the powertrain. The only general rigid parts, besides the engine body, are the diff
outputs and the revolute joints that connect the rigid bodies to the engine body.
Parameters
The following table lists the powertrain system template parameters.
The parameter: Takes the value: Its units are: Description:
phs_kinematic_flag Integer No units When flag = 1, engine is
rigidly mounted to chassis;
when flag = 0, engine is
mounted on bushings. Set
from the Adjust menu.
pvs_clutch_capacity Real Torque Maximum torque clutch can
sustain with zero slip speed.
pvs_clutch_close Real No units Value of clutch demand at
which clutch is fully closed.
Value should be less than
pvs_clutch_open and in the
range of 0 and 1.
pvs_clutch_damping Real Torsional_damping Clutch damping torque per
unit of clutch slip speed.
pvs_clutch_open Real No units Value of clutch demand at
which clutch open.
pvs_clutch_stiffness Real Torsional_stiffness Clutch torque developed per
unit of clutch slip.
pvs_clutch_tau Real Time Time constant for clutch slip
decay when clutch is open.
pvs_ems_gain Real No units Proportional gain used in
EMS idle speed control
pvs_ems_max_throttle Real No units Value of throttle demand that
corresponds to the maximum
capability of the EMS system
175Working with Templates
Communicators
Mount parts provide the connectivity from the template to the body subsystems. Output communicators
publish information, such as engine RPM and transmission spline. The following tables list the input and
output communicators in the powertrain system template.
Input Communicators
pvs_ems_trottle_off Real No units Value of throttle demand at
which EMS system engages
idle speed control
pvs_engine_idle_speed Real RPM Engine idle speed in RPM.
pvs_engine_inertia Real Inertia Engine rotational inertia.
Must be greater than zero.
pvs_engine_rev_limit Real RPM Maximum engine speed in
RPM.
pvs_final_drive Real No units Differential input shaft
(pinion) to ring gear ratio.
pvs_gear_[1-6] Real No units Transmission input shaft to
output shaft ratio for gears 1
through 6.
pvs_graphics_flag Integer No units 1 = include powertrain
graphics; 0 = do not include
powertrain graphics
pvs_max_gears Integer No units Number of gear ratios in the
transmission.
pvs_max_throttle Real No units Value of throttle demand for
which throttle is fully open
(throttle demand = 0 is
throttle closed).
The communicator: Entity class: From minor role: Matching name:
ci[lr]_diff_tripot location inherit tripot_to_differential
ci[lr]_tire_force force inherit tire_force
cis_clutch_demand solver_variable inherit clutch_demand
cis_engine_to_subframe mount inherit engine_to_subframe
cis_initial_engine_rpm parameter_real any initial_engine_rpm
cis_powertrain_to_body mount inherit powertrain_to_body
The parameter: Takes the value: Its units are: Description:
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Output Communicators
cis_sse_diff1 diff inherit sse_diff1
cis_throttle_demand solver_variable inherit throttle_demand
cis_transmission_demand solver_variable inherit transmission_demand
The communicator: Entity class: To minor role: Matching name:
co[lr]_output_torque force inherit output_torque
co[lr]_tripot_to_differential mount inherit tripot_to_differential
cos_clutch_displacement_ic solver_variable inherit clutch_displacement_ic
cos_default_downshift_rpm parameter_real inherit min_engine_speed
cos_default_upshift_rpm parameter_real inherit max-engine_speed
cos_diff_ratio parameter_real inherit diff_ratio
cos_engine_idel_rpm parameter_real inherit engine_idle_rpm
cos_engine_map spline inherit engine_map
cos_engine_max_rpm parameter_real inherit engine_revlimit_rpm
cos_engine_rpm solver_variable inherit engine_rpm
cos_engine_speed parameter_real inherit engine_speed
cos_max_engine_driving_torque solver_variable inherit engine_maximum_driving
_torque
cos_max_engine_braking_torqu
e
solver_variable inherit engine_maximum_brakin
g_torque
cos_max_gears parameter_integer inherit max_gears
cos_max_throttle parameter_real inherit max_throttle
cos_powertrain_gse gse inherit powertrain_gse
cos_transmission_input_omega solver_variable inherit transmission_input_omeg
a
cos_transmission_spline spline inherit transmission_spline
The communicator: Entity class: From minor role: Matching name:
177Working with Templates
Quad-Link Axle Suspension
Overview
The quad-link axle suspension template is an example of a dependent suspension model. The wheels are
mounted at either end of a rigid beam so the movement of one wheel is transmitted to the opposite wheel
causing them to steer and camber together. Solid beam axle suspensions are commonly used on the front
of heavy trucks, where high-load carrying capacity is required.
Figure 12 Quad-Link Axle Suspension
Template name
_quad_link_axle
Note: The engine and clutch portion of the powertrain is implemented as a GSE (general state
equation) element in solver. The gsesub associated with this element is available here.
The solver_variable "analysis_type" indicates whether the analysis is steady-state or
dynamic. When the analysis_type is steady-state the engine torque map and transmission
gear ratios are ignored.
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178
Major role
Suspension
Application
Suspension and full-vehicle assemblies
Description
The quad-link axle suspension template represents a common design for solid axles suspensions. You can
use the template as a front steerable suspension or as rear nonsteerable suspension.
You can set subsystems based on this template to kinematic or compliant mode. In kinematic mode,
Adams/Car replaces the bushings that connect the lower and upper links to the body mount part with the
corresponding purely kinematic constraints.
Files referenced
Bushing, spring, and damper property files
Topology
Spherical joints connect the upper and lower links to the solid axle. The draglink is attached to the bell
crank. The bell crank moves the tie rod, which steers the wheels. Revolute joints connect the uprights to
the solid axle. A joint force actuator locks the hub to the wheel carrier. The following table maps the
topology of the template.
The joint: Connects the part: To the part:
jklhoo_lower_link_frame gel_lower_link mtl_lower_link_frame
jklhoo_upper_link_frame gel_upper_link mtl_lower_link_frame
jklsph_upper_link_axle gel_upper_link ges_axle
jklsph_lower_link_axle gel_lower_link ges_axle
jolrev_knuckle_axle gel_knuckle ges_axle
josrev_bell_crank_axle ges_bell_crank ges_axle
jossph_draglink_pitman_arm ges_draglink mts_draglink_steering
joshoo_draglink_bell_crank ges_draglink ges_bell_crank
jossph_tierod_knuckle ges_tierod gel_knuckle
jolrev_bearing gel_hub gel_knuckle
josinp_tie_rod_bell_crank ges_tierod ges_bell_crank
179Working with Templates
Parameters
Toe and camber variables define wheel spin axis, spindle part, and spindle geometry. The following table
lists the parameters in the template.
Communicators
Mount parts provide the connectivity from the template to body subsystems and steering. Output
communicators publish toe, camber, steer axis, and wheel center location information to the appropriate
subsystems and the test rig. The following table lists the input and output communicators.
Rack and Pinion Steering System
Overview
The rack and pinion steering system is usually found in passenger cars. The pinion gear translates the
rotary motion of the steering wheel into the linear motion of the rack. The rack moves the tie rods back
and forth to steer the vehicle.
The parameter: Takes the value: Its units are:
phs_kinematic_flag Integer No units
pv[lr]_toe_angle Real Degrees
pv[lr]_camber_angle Real Degrees
The communicator: Belongs to the class: Has the role:
ci[lr]_lower_link_frame mount inherit
ci[lr]_spring_upper_to_body mount inherit
ci[lr]_upper_link_frame mount inherit
cis_draglink_steering mount inherit
co[lr]_camber_angle parameter_real inherit
co[lr]_suspension_mount mount inherit
co[lr]_suspension_upright mount inherit
co[lr]_toe_angle parameter_real inherit
co[lr]_wheel_center location inherit
cos_suspension_ parameters_ARRAY any inherit
Note: The kinematic flag variable toggles between kinematic and compliant mode.
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Figure 13 Rack and Pinion Steering System
Template name
_rack_pinion_steering
Major role
Steering
Application
Suspension and full-vehicle assemblies
Description
A series of hooke joints, which connect the three steering column shafts, transmit motion from the
steering wheel to the pinion. A revolute joint connects the lower column shaft to the rack housing. A
bushing (torsion bar) connects the shaft to the pinion. A revolute joint connects the pinion to the rack
housing.
In kinematic mode, a reduction gear is active and connects the steering input shaft revolute joint to the
pinion revolute joint. The underlying Adams/View entity (a coupler) is active only in kinematic mode.
The reduction gear (pinion to rack) converts pinion rotational motion to the rack translational motion. A
181Working with Templates
translational joint constrains the rack to the rack housing. An additional VFORCE provides the steering
assist force.
Files referenced
Property file, mdi_steer_assis.ste, stored in the steer_assist.tbl of the shared Adams/Car database. It
defines the steering assist vector force.
Topology
The following table maps the topology of the template.
Parameters
A parameter variable switches between kinematic and compliant mode. You can set the activity of the
steering assist vector force through the hidden parameter variable, steering_assist_active. A series of
parameters define the maximum values of angle, rack displacement, rack force, and steering-wheel
torque.
Communicators
The following table lists the input and output communicators.
The joint: Connects the part: To the part:
joshoo_column_intermediate ges_steering_column ges_intermediate_shaft
joshoo_intermediate_shaftinput ges_intermediate_shaft ges_steering_shaft
jostra_rack_to_rackhousing ges_rack ges_rack_housing
josrev_steering_wheel ges_steering_wheel mts_steering_column_to_body
josrev_pinion ges_pinion ges_rack_housing
joscyl_steering_column_to_body ges_steering_column mts_steering_column_to_body
josrev_steering_input_shaft ges_steering_shaft ges_rack_housing
jksfix_rigid_rack_housing_mount ges_rack_housing sws_rack_house_mount
steering_assist_vforce ges_rack ges_rack_housing
gksred_input_shaft_pinion_lock josrev_steering_input_shaft josrev_pinion
grsred_steering_wheel_column_lock josrev_steering_wheel joscyl_steering_column_to_bo
dy
grsred_pinion_to_rack josrev_pinion jostra_rack_to_rackhousing
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Rear Driveline System
Overview
The rear driveline system template provides an example model of a driveline for rear-wheel drive (RWD)
vehicles.
The communicator: Belongs to the class: Has the role:
cis_rack_housing_to_
suspension_subframe
mount inherit
cis_rack_to_body mount inherit
cis_steering_column_to_ body mount inherit
co[lr]_tierod_to_steering mount front
cos_max_rack_ displacement parameter_real inherit
cos_max_rack_force parameter_real inherit
cos_max_steering_angle parameter_real inherit
cos_max_steering_torque parameter_real inherit
cos_steering_rack_joint joint_for_motion inherit
cos_steering_wheel_joint joint_for_motion inherit
Note: The rack and pinion steering system template contains general spline elements. The
gss_torsion_bar spline gives the torque as a function of the angular deflection of the input
shaft relative to the pinion.
The template also contains a switch part, which lets you explore two different topological
solutions. You can connect the steering rack housing to the body or to the
suspension_subframe.
183Working with Templates
Figure 14 Rear Driveline System
Template name
_driveline_rwd
Major role
Driveline
Application
Full-vehicle assemblies
Description
The rotational motion of the front propshaft is transmitted to the rear shaft and from there to the diff
outputs. Diff outputs should be connected to the driving wheels.
Files referenced
Bushing property files
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Topology
The rear driveline template consists of a two-piece propshaft, a slip yoke, and a differential. For
convenience, the template includes the propshaft input part for applying motion or torque. The propshaft
input part attaches to the powertrain through a revolute joint. A bearing supports it at its aft.
The front propshaft attaches to the support bearing through an inline joint primitive that prevents
translation of the front propshaft perpendicular to the propshaft's spin axis.
Hooke joints transmit the motion to the slip yoke part. The slip yoke supports and transmits torque to the
rear propshaft through a translational joint. The differential input shaft receives torque from the rear
propshaft through a hooke joint.
The differential is an open design rather than a limited slip. Four bushings mount it to the body. Setting
kinematic mode fixes the differential housing to the body and deactivates the bushings. The following
table maps the topology of the template.
Parameters
The parameter variable final_drive_ratio defines the pinion to ring ratio.
The joint: Connects the part: To the part:
josrev_diff_input ges_diff_input ges_diff_housing
jolrev_diff_output gel_diff_output ges_diff_housing
jorrev_diff_output ger_diff_output ges_diff_housing
joshoo_propshaft_at_diff ges_propshaft_rear ges_diff_input
joshoo_propshaft_input_to_ front ges_propshaft_input ges_propshaft_front
joscon_propshaft_front_to_ yoke ges_propshaft_front ges_slip_yoke
jostra_propshaft_rear_to_yoke ges_propshaft_rear ges_slip_yoke
josrev_propshaft_input_to_ trans ges_propshaft_input mts_propshaft_input_to_powertrai
n
jksfix_diff_housing_to_body ges_diff_housing mts_diff_housing_to_body
josinl_support_bearing_to_propshaft_f
ront
ges_support_bearing ges_propshaft_front
josori_support_bearing_orientation ges_support_bearing mts_propshaft_support_to_body
josinp_support_bearing_ location ges_support_bearing mts_propshaft_support_to_body
jksinl_support_bearing_to_ body ges_support_bearing mts_propshaft_support_to_body
grsdif_differential josrev_diff_input jolrev_diff_output
grsdif_differential josrev_diff_input jorrev_diff_output
grsdif_differential jolrev_diff_output jorrev_diff_output
185Working with Templates
Limitations
The rear driveline template uses a number of rotating parts. If the driveline dynamics are not of interest
to you, then it is more efficient to apply direct drive torque to the wheels, because the rotating parts in
the template might slow the numerical integration during the analysis.
Communicators
Output communicators of the type mount publish the left and right differential output shafts to the
suspension templates and subsystems. The following table lists the input and output communicators.
Rigid Chassis
Overview
The rigid chassis template represents the base frame of a vehicle.
The communicator: Belongs to the class: Has the role:
ci[lr]_tripot_to_differential location rear
cis_diff_housing_to_body mount inherit
cis_driveline_torque solver_variable inherit
cis_propshaft_input_to_ powertrain mount inherit
cis_propshaft_support_to_ body mount inherit
co[lr]_tripot_to_differential mount rear
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Figure 15 Rigid Chassis
Template name
_rigid_chassis
Major role
body
Application
Suspensions, tires, and steering systems in full-vehicle assemblies
Description
A single rigid body part models the chassis.
Files referenced
Shell elements create the chassis graphic. All the shell files are stored in the Adams/Car shared database,
in the shell_graphics.tbl directory.
Topology
The ges_chassis part is unconstrained.
Parameters
The rigid chassis template defines a series of parameter variables, most of which are used to compute the
aerodynamic forces acting on the body. The following table lists the parameters in the template. For a
detailed description of the force function, see Force Function Description.
Force function description
Adams/Car expects air density and area parameter variables to be in model units.
As a result of an air stream interacting with the vehicle, forces and moments are imposed on the vehicle.
Out of the three forces and three moments, only the most relevant ones are modeled in the template. The
aerodynamic general force takes into consideration the drag force (longitudinal force) and torque
(pitching moment and torque along the y-axis of the vehicle, in the SAE coordinate system). In detail:
The parameter: Takes the value: Its units are:
pvs_aero_drag_active Integer No units
pvs_aero_frontal_area Real Area
pvs_air_density Real Density
pvs_drag_coefficient Real No units
187Working with Templates
F = 0.5 x AirDensity x DragCoeff x Area x VX(chassis)2
T = F x DZ (RideHeight)
The pitching moment acts to transfer weight between the front and rear axles. It arises because the drag
does not act at the ground plane. Therefore, it accounts for the elevation of the drag force.
Limitations
The rigid body modeling of the chassis does not account for torsional stiffnesses and other effects. You
could create a more accurate representation of a chassis frame by connecting the multiple rigid bodies
though spring dampers to take into account torsional stiffnesses and using modal flexibility.
Communicators
The rigid chassis template defines a series of mount part communicators. The assembly process matches
them with the corresponding output communicators created in suspensions, steering, and other
subsystems. The following table lists the communicators. Note that the output communicator
tierod_to_steering (rear) allows the tierod_to_steering mount parts in the rear suspension to connect to
the chassis body.
The communicator: Belongs to the class: Has the role:
co[lr]_spring_to_body mount inherit
co[lr]_strut_to_body mount inherit
co[lr]_tierod_to_steering mount rear
co[lr]_tv_link mount inherit
co[lr]_uca_to_body mount any
co[lr]_upr_link_fr mount inherit
co[lr]_upr_link_rr mount inherit
cos_aero_drag_force force inherit
cos_body mount inherit
cos_body_subsystem mount inherit
cos_chassis_path_ reference mount inherit
cos_concept_to_body mount inherit
cos_diff_housing_to_body mount rear
cos_driver_reference mount inherit
cos_measure_for_distance mount inherit
cos_powertrain_to_body mount inherit
cos_propshaft_support_to_body mount rear
cos_rack_to_body mount inherit
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Simple Anti-Roll Bar System
Overview
The simple anti-roll bar system template represents a bar fitted transversely to the suspension. The bar is
made out of steel or a user-defined material. The bar is installed in a vehicle to reduce the roll of the
vehicle body as the vehicle takes a corner. It increases suspension roll rate.
Figure 16 Simple Anti-Roll Bar System
Template name
_antiroll_simple
cos_steering_column_to_ body mount inherit
cos_subframe_to_body mount inherit
cos_aero_force force inherit
The communicator: Belongs to the class: Has the role:
Note: The rigid chassis light template (_rigid_chassis_lt) is exactly the same as the rigid chassis
template (_rigid_chassis), but without the shell graphic geometry.
189Working with Templates
Major role
Antiroll
Application
Suspension and full-vehicle analyses
Description
The anti-roll bar system template provides a simple model of anti-roll bar (also known as stabilizer bar).
It consists of two bar halves connected by a torsional spring-damper component.
Files referenced
Bushing property files
Topology
A revolute joint connects the two bar halves of the anti-roll bar system. Bushings then attach the bar
halves to the body or to the suspension subframe. Drop links transmit the suspension motion to the bar
ends. The drop links attach to the suspension with spherical joints and to the bar ends with convel joints.
The following table maps the topology of the anti-roll bar system template.
Parameters
A parameter variable (pvs_torsional_stiffness) defines the torsional stiffness of the spring-damper
component. The following table lists the parameter, its value, and units.
Limitations
The anti-roll bar system template represents a simple approximation of a stabilizer bar. For more
complex solutions, you would need to create a more accurate representation of the bar through the
discretization of rigid bodies, nonlinear rods, or flexible bodies.
The joint: Connects part: To part:
jo[lr]sph_droplink_ upper_bal ge[lr]_droplink mt[lr]_droplink_to_suspension
jo[lr]con_droplink_to_arb ge[lr]_droplink ge[lr]_arb
josrev_arb_rev_joint ger_arb gel_arb
arb_torsion_spring (rotational
spring)
ger_arb gel_arb
The parameter: Takes the value: Its units are:
pvs_torsional_stiffness Real variable Nmm/Degrees
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190
Communicators
Mount parts provide the connectivity to the suspension subsystems. An output communicator exports
information about the location of the ARB pick-up point.
The following table lists the communicators that the template uses.
Tire System
Overview
The tire system template provides three basic functions:
• Supports vertical load.
• Develops longitudinal forces for acceleration and braking.
• Develops lateral forces for cornering.
The communicator: Belongs to the class: Has the role:
ci[lr]_arb_bushing_mount mount inherit
ci[lr]_droplink_to_suspension mount inherit
co[lr]_ARB_pickup location inherit
Notes: The spring-damper component applies a rotational action-reaction force between the two
bar halves. The following linear equation describes the torque applied at the i marker:
Ta = -C(da/dt) - Kt (a - ANGLE) + TORQUE
where:
• C is the damping term (defaults to 0 in the template).
• Kt is the torsional stiffness.
• a is the angle between the bar halves.
• ANGLE is the initial angular displacement.
• TORQUE is the torsional preload. Torque applied on the j marker is equal and
opposite to the torque on the i marker.
191Working with Templates
Figure 17 Tire System
Template name
_handling_tire
Major role
Wheel
Application
Full-vehicle analyses
Description
The tire system template consists of wheel parts rigidly connected to mount parts. The tire contact patch
forces are transformed in forces and torques applied at the hub. A series of user-written subroutines
perform the force calculation depending on the tire property file that you selected. The contact type
(string element) and the road property file determine the road model. For additional information about
using Adams/Tire in Adams/Car, see the Adams/Tire online help.
Files referenced
The tire system template references a tire property file for each wheel part. The default tire property file
is mdi_tire01.tir, stored the tires.tbl directory of the Adams/Car shared database.
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192
Topology
A fixed joint connects the wheel part to the spindle mount part.
Communicators
Mount parts provide connectivity to the suspension subsystems, and output communicators publish
information about tire forces and wheel orientation.
The following table lists the communicators in the tire system template.
Torsion Bar Double-Wishbone Suspension
Overview
The torsion bar double-wishbone suspension template is a modified version of the standard Double-
Wishbone Suspension. In this template, however, a torsion bar spring replaces the coil spring.
The communicator: Belongs to the class: Has the role:
ci[lr]_camber_angle parameter_real inherit
ci[lr]_suspension_mount mount inherit
ci[lr]_toe_angle parameter_real inherit
ci[lr]_wheel_center location inherit
cis_driveline_active parameter_integer inherit
co[lr]_rotor_to_wheel mount inherit
co[lr]_wheel_orientation orientation rear
cos_tire_forces_array_left array inherit
cos_tire_forces_array_right array inherit
193Working with Templates
Figure 18 Torsion Bar Double-Wishbone Suspension
Template name
_double_wishbone_torsion
Major role
Suspension
Application
Suspension and full-vehicle assemblies
Description
In the torsion bar double-wishbone suspension template, a torsion bar spring replaces the coil spring used
in the standard Double-Wishbone Suspension. The torsion bar consists of two bar halves connected by
a rotational SFORCE (joint torque actuator). The rotational SFORCE exerted between the two bar halves
is a function of a torsional stiffness and of the relative rotation along the torsion bar longitudinal axis.
Files referenced
Refer to the Double-Wishbone Suspension.
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194
Topology
The torsion bar consists of two bar halves connected by a cylindrical joint and a joint torque actuator. The
first half is rigidly connected to the lower control arm, and the second half is fixed to the mount part and
gets rigidly connected to the chassis if you use the suspension in full-vehicle assemblies.
Parameters
The torsion bar double-wishbone suspension template includes additional parameter variables besides
those described in the Double-Wishbone Suspension. The variable defining the torsional stiffness defines
the torsion bar stiffness. Also, another parameter variable defines the torsional preload applied between
the lower control arm and the torsion bar.
The following table lists the additional parameters.
Communicators
Refer to the Double-Wishbone Suspension.
Trailing Arm Suspension
Overview
The trailing arm suspension template is one of the most simple and economical designs for independent
suspensions.
The parameter: Takes the value: Its units are:
pv[lr]_tbar_stiffness Real Nmm/Degrees
pvs_tbar_preload Real Nmm
Note: The torsion bar double-wishbone suspension template includes a toe adjustment. It uses an
adjustable force Adams/Car element to reach a desired toe angle at static equilibrium.
195Working with Templates
Figure 19 Trailing Arm Suspension
Template name
_trailing_arm
Major role
Suspension
Application
Suspension and full-vehicle assemblies
Description
The trailing arm suspension template is a simple non-steerable suspension design. You can deactivate the
driveline simply by selecting inactive in the Toggle Driveline Activity dialog box. Note that it is possible
to define the spring concentric to the damper just by moving the spring upper- and lower-seat hardpoints.
Files referenced
Bushing, spring, damper, bumpstop, and reboundstop property files
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Topology
Trailing arms to the left and right sides mount to a rigid subframe that in turns connects to the body mount
part through bushings. The arms alone locate the wheel centers. Springs and dampers act between the
arms and the body mount parts. A static rotation control actuator locks the rotational degree of freedom
of the hub during quasi-static analyses.
You can set the suspension to kinematic or compliant mode. Kinematic mode allows purely kinematic
connections between the upper strut parts, arms, subframe, and mount parts, while compliant mode
replaces the kinematic joints with their corresponding elastic elements.
The following table maps the topology of the template.
Parameters
The driveline offset variable defines the driveline geometry. Toe and camber variables define wheel spin
axis, spindle part, and spindle geometry.
Communicators
Mount parts provide the connectivity from the template to the body subsystems. Output communicators
publish toe, camber, steer axis, and wheel-center location information to the appropriate subsystems and
the test rig. The following table lists the input and output communicators.
The joint: Connects the part: To the part:
jklhoo_upr_strut_to_body mtl_strut_to_body gel_upper_strut
jklrev_arm_inner_ pivot gel_arm ges_subframe
jksfix_subframe_to_body_fixed ges_subframe mts_subframe_to_body
jklhoo_lwr_strut_to_arm gel_lower_strut gel_arm
jolcyl_lwr_upr_ strut gel_upper_strut gel_lower_strut
joltra_tripot_to_ differential gel_tripot mtl_tripot_to_differential
jolcon_drive_sft_ int_jt gel_tripot gel_drive_shaft
jolrev_spindle_ upright gel_spindle gel_arm
The parameter: Takes the value: Its units are:
phs_kinematic_flag Integer No units
pv[lr]_toe_angle Real Degrees
pv[lr]_drive_shaft_offset Real mm
phs_driveline_active Integer No units
pv[lr]_camber_angle Real Degrees
197Working with Templates
Twist Beam Suspension
Overview
The twist beam suspension is a dependent suspension model intended for use only as a rear suspension.
It does not include a panhard rod.
The communicator: Belongs to the class: Has the role:
ci[lr]_spring_to_body mount inherit
ci[lr]_strut_to_body mount inherit
ci[lr]_tripot_to_differential mount inherit
cis_subframe_to_body mount inherit
co[lr]_camber_angle parameter_real inherit
co[lr]_suspension_mount mount inherit
co[lr]_suspension_upright mount inherit
co[lr]_toe_angle parameter_real inherit
co[lr]_tripot_to_differential location inherit
co[lr]_wheel_center location inherit
cos_driveline_active parameter_integer inherit
cos_suspension_
parameters_ARRAY
array inherit
Note: The kinematic flag variable toggles between kinematic and compliant mode.
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198
Figure 20 Twist Beam Suspension
Template name
_twist_beam
Major role
Suspension
Application
Suspension and full-vehicle assemblies
Description
The twist beam suspension template represents a common rear dependent suspension design. It does not
include a subframe. The suspension is non-steerable and intended to be used as a rear suspension only.
The twist beam is a flexible body generated using shell elements. Interface parts connect the flexible
body to the rest of the suspension.
You can toggle the suspension between kinematic and compliant modes. In addition, you can deactivate
driveshafts.
199Working with Templates
Files referenced
Springs, dampers, and bushings property files. Also, the flexible body references the file PonteV.mnf,
stored in the flex_bodies.tbl directory of the Adams/Car shared database.
Topology
A static rotation control actuator locks the rotational degree of freedom of the hub during quasi-static
analyses.
The following table maps the topology of the twist beam suspension.
Parameters
In the twist beam suspension, toe and camber variables parameterize wheel spin axis, spindle part, and
spindle geometry. The following table lists the parameters in the template.
Communicators
The following table lists the communicators in the template.
The joint: Connects the part: To the part:
jklhoo_upr_strut_to_body mtl_strut_to_body gel_upper_strut
jolcyl_lwr_upr_strut gel_upper_strut gel_lower_strut
joltra_tripot_to_differential gel_tripot mtl_tripot_to_differential
jolcon_drive_sft_int_jt gel_tripot gel_drive_shaft
jolcon_drive_sft_otr gel_drive_shaft gel_spindle
jolhoo_strut_to_beam gel_lower_strut ipl_damper_lwr
jklrev_beam_to_body ipl_beam_to_subframe mts_body
jolrev_spindle_to_beam gel_spindle ipl_spindle_to_beam
The parameter: Takes the value: Its units are:
phs_driveline_active Integer No units
phs_kinematic_flag Integer No units
pv[lr]_toe_angle Real Degrees
pv[lr]_camber_angle Real Degrees
pv[lr]_drive_shaft_offset Real mm
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200
The communicator: Belongs to the class: Has the role:
ci[lr]_spring_to_body mount inherit
ci[lr]_strut_to_body mount inherit
ci[lr]_tripot_to_differential mount inherit
cis_body mount inherit
co[lr]_camber_angle parameter_real inherit
co[lr]_suspension_mount mount inherit
co[lr]_toe_angle parameter_real inherit
co[lr]_tripot_to_differential location inherit
co[lr]_wheel_center location inherit
cos_driveline_active parameter_integer inherit
cos_suspension_parameters_ARRAY array inherit
Note: The integer parameter variables let you activate and deactivate the driveshafts. The
kinematic flag variable toggles between kinematic and compliant mode.