2 Design Report

8/10/2019 2 Design Report

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2.3gm/km, HC 0.2gm/km, NOx0.15gm/km).

Fuel economy: Upto 15 kmpl

3D VIEW OF THE COMPLETE

VEHICLE

FRONT VIEW

SIDE VIEW

ISOMETRIC VIEW

ROLL CAGE DESIGN & DRIVER

ERGONOMICS

Design Considerations

Place of seat, steeringAll levers, switches should be in reach ofdrivers hand

sufficient Leg room, head roomFire executor will near to the feet. Driver

and external human both should reach.

Weight of roll cage = 72 kg (approx).

Material usedThe commonly used materials for

tubing are 1018 Mild Steel. The frame will

be built using MIG welding.Material Properties:

OD: 26.9mmID: 21mmDensity: 7860kg/mm3

C %: 0.18

AnalysisThe user friendly ANSYS is used for

the analysis of the roll cage. The conditions

are given below.

FRONT COLLISION ANALYSIS

In this case a deceleration of 10 Gsis the assumed loading. This is equivalent toa 33375N load on the vehicle. In image of

the FEA, the scale shows stress distribution.

RESULTS:

Deflection: 2.244mm


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Von misses stress: 260.577mm2

Side collision analysis

Side impact is analyzed with a 5 Gload. This is equivalent to a loading force of

16687.5N. The area of application of this

force is SIM and LFS.

RESULTS;

Deflection: 18.114mmVon misses stress: 369.177 N/mm2

SHOCK MOUNT IMPACTANALYSIS

In this case, shock mounts caused bya 5 G load on it. This is equivalent to a

loading force of 3800N on single front

wheel. The resulting stresses from thisloading are seen in Figures.

RESULTS;

Deflection: 11.646mm

Von misses stress: 363.064 N/mm2

ROLLOVER IMPACT ANALYSIS

In this case, the stress on the rollcage is caused by a rollover with a 2.5 G

load on the cage. This is equivalent to aloading force of 8343N. The Loading isapplied to the upper forward corner of the

perimeter hoop. The load is chosen to be ona single corner as this would be a worst case

scenario rollover.

RESULTS;

Deflection: 5.77mmVon misses stress: 157.551N/mm2

DRIVER ERGONOMICS

Driver ergonomics is one of most

important thing in ATV vehicle design. The

vehicle is designed with considering the

easy reach to all switches placed in driver

cabin, proper handling grip to steering, the

seating position is maintained to have good

grip to gear lever, hand brake lever. Cabin is

designed to easy entry and exit to vehicle.

ABC pedals are placed ergonomically and

ensured the effort less pedal activation.

Front side is maintained at low position so

that there should not be any blind spot for

driver.


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SUSPENSION DESIGN

A Suspension acts to provide cushioningaction to the driver by absorbing the shocksfrom the road and also helps the tires to

maintain good traction.

We are going to use independent doublewishbone suspension.

1. It gives more movement of the tires and to

the spring than Mac person strut type.

2. We can distribute forces at different pointon roll cage.

3. Desired camber angle, castor angle and

ground clearance can be achieved.

Front Suspension Design

By using Catia V5 R18 we have

found following specifications.

W=mass of vehicle with driver = 410kg

Sprung mass=95kg

Max. Travel of the wheel centre: 210mm

Camber variation: 2 (at droop) to -1 (at

bump)

Fig: Suspension geometry

At 4g load,

R=49.8195/2=1878N

=12.783 =6.469 r=19.415

a=338.784mm b=244.247mm =25.44

P=R1/ (sin +cos cot r) =618.7257 N

Q=R1sin(r-)/ (sinrtan+cosr)

=1860.1150N

U=R1/ (sin r tan +cos r) = 1815.2107N

S=U a/b=2517.7969N

Load on spring = F = S/cos = 2788.15N

For 1g load,

R=19.8195/2=470 N

=20.392 =20.531 r=27.482

a=373.792mm b=247.133mm =20.435

P =R1/ (sin +cos cot r)= 214.9452N

Q=R1sin(r-)/ (sinrtan+cosr) =

495.8701N

U=R1/ (sin r tan +cos r) =436.5934

N

S=U a/b=660.3534N

Load on spring=F=S/cos =704.7N

Therefore, Net load =2083.45N

n=14 C=7.5 d=12mm D=90mm

Spring length: 317 mm

No. of springs=2

Spring stiffness (K): 24.11 N/mm

Deflection = 8nFD3/Gd4=137 mm


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Maximum working shear stress

= k*8*F*D/*d3=516.88 N/mm

Rear Suspension Design

Sprung mass=245kg

Max travel of the wheel centre: 150mm

Camber variation:2(at droop) to -4(at

bump)

For 4g load, R=4*9.81*295/2=4794 N

=28.091, =5.509, r=5.329,

a=302.577mm, b=259.77mm, =9.337

P=482.78N, Q=4822.31N, S=5413.29N

Load on spring=F=S/cos =5485.97N

For 1g load,

R=1*9.81*295/2=1199 N

=3.842, =8.491, r=6.007,

a=379.949mm, b=280.99mm, =10.229

P rear=125.49N,Q rear=1208.50N

S rear=1617.89N

Load on spring=F=S/cos=1644N

Therefore, Net load =3841.97N

n=12 C=7.5 d=8mm D=60mm

Spring stiffness (K): 13.77 N/mm

Spring length: 217 mm

No. of springs=4

Deflection=8nFD^3/Gd^4=110mm

Maximum working shear stress

=k*8*F*D/*d3=541.5 N/mm2

STEERING DESIGN

Steering system is the most basiccomponent of any vehicle. Here, we areusing a non assisted (manual) steering

system, governed by the Ackermansprinciple, as it is the best known principle in

steering governing with a very effectiveturning of the vehicle without dragging thewheels.

Rack and pinion steering systemselected for its higher stability and lower

effort. Its easier to steer and less susceptible

to failures. Steering ratio will be nearly17.Steering geometry ensures the

ACKERMANs principle at normal steeringangle 37degree.

Correct steering angle calculations

Cot()Cot()=track/base

Cot(25.65)Cot(36.412)=0.7267

C/b=1210/1670=0.7245

Hence, Ackermans principle satisfied.

Fig: Ackermans principle

Turning radius=(b/sin )+(a-c)/2


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=(1670/sin25.65)+(1350-1210)/2

=3.92meter

Layout:

Rack and Pinion guided steeringsystem,mounted on rollcage with suitable

brackets,acting on Maruti800wheel hub.

Rear steering uses same Rack and

wheel hub.Steering effort is transmitted to

rear rack by using pair of bevel gears,intermediate shaft and clutch arrangementfor optional engagement and disengagement

of rear rack.

Steering Effort

Front wheel steering ratio=17:1

Weight on front wheels(m1)=115kg.

Wheel scrub radius(r)=34.5mm.

Torque to rotate frontwheels(Mtr)=(m1)x(r)x9.81=39675N-mm

We selected wheel-hub of Maruti-800,

Steering armlength(l)=165mm

Pinion dia.(d)=3mm

Force on the rack(P)=Mtr/l=240.45N

Torque on pinion,(Mtp)=Pxd/2=3606.8N-mm

Steering wheel dia.(D)=300 mm.

Mech.efficiency of system(m)=0.85

Steering Effort=Mtp/(D x m)=2.88 kg-f

Brake System Design

Description:

Disc brakes: Of MARUTI-800 for all

wheels.

System: Hydraulic Diagonal Split

System.

TMC: KBX master cylinder.

Calculations:

Assuming a car at 60 kmph will stop

covering a distance of 20m,

Retardation a=6.9445 m/s2=0.7079 g

Braking force = mass a

=4106.9445

=2847.24 N

PART 1:

CG height: h=564.287mm.

Lf,Lr=Reactions on respective wheel

In static condition:

Lf+Lr= 4022.1 N

Lf1200=Lr470

Thus,Lf=1131.96 N,Lr=2890.13 N

In dynamic condition:

Lf1200=2847.245564.287+Lr470

Lf=2094.043 N,Lr =1928.057 N

Accounting the weight transfer,

470mm1200mm

Fig : Forces involved in Braking


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Torque on single front wheel:

Tf = (2094.043 (29.81)) 0.31756.9445

= 235.3267 Nm

Similarly, Tr =216.662 Nm

Total torque:

T=2 (235.3267 +216.662)

=904 Nm

PART2:

Force that can be applied by right foot for 5th

percentile female is 445 N.

The pedal leverage: 1:5

TMC OD: 19.05mm

So pressure obtained is

P= (1205)/ (0.019052/4)

=2.105106N/m

2

=21.05 bar

Now torque applied:

T=2PARf n

=22.105106 0.051

2/40.30.09154

=944.30 Nm

The required torque is 904 Nm

The applied torque will be 944.30Nm

Hence it will be enough to stop the car.

Pedal force and deceleration: For maxpedal force of 445N, the deceleration of 1g

is achieved when the vehicle is fully loaded.

In our case,

For =0.3

The ratio between peal force anddeceleration is found to be 163g.

The deceleration increases with pedal force

and some values are,

f=80N; d= 4.83 m/s2 , f=120N; d=7.25

m/s2

f=100N; d= 6.04 m/s2

, f=140N; d=8.46m/s

2

POWERTRAIN DESIGN

Gearbox: 4 speed constant mesh manual,

M&M Alfa champion.

Gear Gear ratios kmph per

1000 rpm of

engine

1st 31.48 3.80

2n

18.70 6.40

3rd

11.40 10.50

4th

7.35 16.28

Reverse 55.08 2.17

Gear

Max. Speed

in Gear in

Kmpl

Max.

Gradability in %

(At Speed in

kmpl)

1st

13.69 43.43 (9.89)

2n

23.04 22.51 (16.64)

3r

37.80 11.55 (27.30)

4t

58.63 5.18 (35.83)


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Safety equipments are selected on the basis

of rule book and the safety ratings and to

minimize the occurrence and consequences

of automobile accidents. Active safeties are

well designed truss body to absorb energy

and passive safeties are all mentioned above.

All passive safety equipments are mounted

on vehicle with taking care of the rules and

regulations.

COST & BILL OF MATERIALS

The cost report is based on Bill of

Materials concept.

Sr.

no.

System No. of

parts

Total

cost(Rs)

1. Engine 12 31030.25

2. Transmission 16 22989.19

3. Suspension 23 24999.62

4. Wheels 7 38881.64

5. Brake 23 9899.98

6. Steering 38 12720.87

7. Body 12 41762.74

8. Electrical 13 15050.00

Material procurement cost = Rs.

160929.18

Manufacturing cost = Rs. 36414.11

Total cost = Rs. 197343.29

INNOVATIONS

Optional four wheel steering:

We have designed optional 4Wsteering. The driver can use front wheel or

four wheels steering to turn the vehicle. Use

of four wheel steering gives turning radiusof 2.9m.

4W Steering Effort

Weight on rear wheels (both) m2=294 kg.

Rear wheel scrub radius(r) = 34.3mm.

Torque to rotate rear wheels, (Mtr) =m2x r x9.81=100842N-mm

For selected steering assembly,

Steering arm length (l)=165mm

Pinion dia.(d)=30mm

Steering wheel dia. (D) =300mm.

Force on the rack (P) = Mtr/l=611.2N

Torque on pinion (Mtp) = P x d/2=9167.4N-mm

Mech. efficiency of the system (m)=0.9

Steering Effort=Mtp / (D x m) =6.9 kg-f

Effective Torque = (Mtpf + Mtpr)/3=6662.6N-mm

4WS effort=5.03 kg-f

We will be using split braking forrear wheels as present in tractor for

more turning.

GO GREEN COMPLIANCE

Today the emissions from

vehicles are the major concern to theenvironment degradation. So the emission

control is an important aspect in automobileindustry.

We are opting for BS-III norms of emission.(CO 2.3gm/km, HC 0.2gm/km, NOx

0.15gm/km).

Three way catalytic converter isused to reduce CO, HC, NOx emissions. The

maximum use of recyclable and eco-friendlymaterials is considered in vehicle designing.


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