Optimizing Parameters

Are you Optimizing Your Parameters?

Design to Production – Traditional Method and Challenges

70% of the final product cost is determined during the design stage. DFMA is typically a team advisory approach with minimal rigor and no method for optimization.

Background:

• Perfect manufacturing is impossible in the real world

• Products must be designed with proper functionality, yet with enough geometric leeway to be effectively manufactured

• Product design incorporates geometry, motion, forces and tolerancing

• Optimization of these parameters is vital for cost-effective product design for manufacturing and assembly (DFMA)

A single ECN can end up costing tens of thousands — in some cases even millions — of pounds in tooling changes, scrap and rework, change validation, warranty repairs and recalls.


Parameter Optimization

Parameters Considered• Geometry

• A general idea of the part shape and geometries is used to begin the design process

• Motion• Understanding and modeling the

kinematics of the mechanism places constraints on the geometries

• Forces• Must be modeling and analyzed to

determine optimum part function and material choices

• Tolerances• Tolerances are necessary to optimize

the overall part features and function, and the manufacturing process against overall development costs

Challenges

• Geometry

• Geometries at beginning stages must be loose so they do not overly constrain motion and tolerances

• Motion

• Sufficiently defined geometries allow accurate motion simulation

• Forces

• Dependent on geometric and kinematic constraints

• Tolerances

• Tolerances depend on and determine geometries, motion and forces

Optimizing all of these parameters together allows the part/assembly to be as effective, manufactural and cost efficient as possible.


Current DFMA Areas:

• Miniaturization & Tolerance Truncation• Designing to, and meeting smaller

tolerances produces better, more reliable, and more powerful products more cheaply

• Most common tools are simple spreadsheets. Manual calculations are slow, tedious, error prone

• Cycle-time Competing with Precision Requirements• Stricter requirements require longer

initial, detailed and prototyping design phases. Longer cycle-times are bad for competitive engineering/design/manufacturing businesses

• Modeling Kinematic Mechanisms• Allows the derivation of the kinematic

function from a specification of its parts’ shapes and motion constraints


• Manual reviews

• Cumbersome

• Time consuming

• Prone to errors

• Lack tools to enforce the checks

• Experienced design/manufacturing personnel are retiring and leaving positions

• Their knowledge needs to be captured and leveraged across design teams

• Companies are trying to balance the tradeoffs between

• Time to market

• Product costs

• Production yields

It is a difficult equation to solve – compounded by offshore manufacturing

High-Risk Issues

• Inability for designers to represent functional intent through engineering drawings and specifications

• CAD models lose a lot of value and information since they are unable to

demonstrate the function and interconnection of

• Modeling the interaction of parts allows detailed communication throughout the entire development team

• Enables quick and easy determination/elimination of problem areas

• Individuals are not trained to optimally and inspect product to engineering drawings and specifications

How Companies can Solve These Problems

Two options exist to model and test kinematics:

• Prototyping

• Very costly and time consuming. Initial prototypes are built with estimations –geometries, tolerances etc. not fully defined

• Computer simulations

• Software must be able to analyze and display motion of components in at least 2D. Making changes should display results in real time, allowing fasting optimization

How Design Teams are Optimizing Parameters

Computer simulations are indispensible

• Ideally, a simulation tool will be:

• An equation solving system that's also a geometric modeling tool

• A tolerance analysis tool that’s also an integral part of the conceptual design process

• A sophisticated GD&T tool that also models kinematics, forces, and virtually any physical phenomenon described with equations

• A critical parameter optimization system that also includes variation

Enventive

Enventive is a full-featured mechanical engineering design system that supports intelligent modeling, incorporating product function in geometric models.

• Develop full working, dynamic models of mechanisms, including kinematics and internal forces

• Designers/engineers can represent intended function through engineering drawings and specifications

• Mechanism/force/performance modeling – see how parts interact and how the resulting tolerance analysis changes as geometries do

• Design with tolerances in mind from the start

• Instant result display for efficient “what-if” scenario analysis

• Getting closer to the final design earlier in the design process

Examples of clients using Enventive

Enventive

• Rapidly inspect , determine and eliminate problem sources as they arise

• Analyze and optimize performance parameters directly from the tolerance report

• Problems in prototyping/manufacturing, reduce the downtime associated with redesigning by fixing the source immediately

• Fully dependent on equation modelling

• Allows representation of internal mechanism forces

• Enventive stores mathematical information – CAD tools do not compare

• Internally integrated with Excel spread sheets

• Engineers won’t lose their engineering spread sheets, or the familiarity they have with them

Enventive Capabilities

Design/Modeling/Sketching Capabilities:

• Sketches and graphical representations of the parts drive the models

• Contains mathematical relationships between CAD surfaces

• Allows modelling of exact contact points

• Normal and friction forces directly at the contact points in complex mechanical shapes

• pawl / claw, cam / profile, pin / hole

• Used in preliminary designs to make decisions on nominals and tolerances of key design parameters

• Including all functional tolerance and design aspects

• Forces, frictions, complex contacts, wear and deformation

• Pre-CAD stage tolerance analysis

• Communication with manufacturing can begin earlier

• Callouts clearly justified and critical features fully understood

Optimization/Variation Capabilities:

• Performs variation analysis and optimization for any parameter

• Geometric parameters: travel, forces, gaps, pressure, friction, and assemble-ability.

• Non-geometric parameters: spring forces, deflections, stress, thermal or electrical properties, and cost

• Includes variation from orientation constraints

• Parallelism and perpendicularity

• Accounts for the orientation variation implied by feature of size tolerances

• Ability to quickly optimize all the important design parameters and tolerances of mechanical designs

• Important functional parameters of those designs are within specifications

• Design software that gives you power

• Choose materials and manufacturing processes

• Detailed design based on knowledge about performance requirements and variation


Calculation/Analysis Capabilities:

• Sensitivity values are calculated for each contributor

• Key contributors are clearly identified

• Easily perturb each feature to visualize its impact

• Easily analyze kinematics and free-body diagrams

• Forces and moments through a mechanism’s entire range of motion, including the contributions of frictional forces

• Diverse types of complex analyses:

• Complex kinematics

• Complex ISO tolerancing

• Physical aspects (forces, contacts): need for DOE and prototypes reduced


Enventive Portfolio

Cost/Supplier Analysis and Capabilities:

• Structured Cost Optimization for Transfer Functions:

• Number of contributors

• Sensitivities

• Tolerances

• Process Capabilities

• Tolerances on small impacts contributor

• Consider the Price / Robustness ratio proposed by a new supplier

• Check the interaction of design variability between two subsystems provided by two suppliers

Enventive Parameter Optimization Examples

• Enabling engineers to embed formulas computing functional properties in component models.

• Engineers can examine and modify graphical and mathematical views of their model simultaneously.

• Changes automatically reflected in model, sketch, equations, and parameters

Latch system operating in 3D including transmission by cable:



Electrical Engine (Analysis of rotor / stator electrical gaps)

Camshaft accuracy analysis:


Enventive Features: Product Overview

Enventive Highlights

Tolerance Analysis

Conceptual Design

Travel and Effort Studies

Mechanisms & Tolerance-in-Motion

Performance Modeling

Optimization

Smart Components

Enventive Benefits

Easier to learn and use than similar tools

Combines geometry, variation, kinematics and loads

Combines geometric and non-geometric data

Embeds spreadsheet analysis

Can be connected to CAD models via SQL

Automatic detection of contributors

Comments from Enventive Users…

“We can conceptualize design concepts ten times faster in Enventive than we can with our native CAD system…

Rather than seeking to simply avoid problems, by using tolerance-based optimization early in the product development process, well up-front of traditional CAD, we’re able to use Enventive to target and achieve optimized design solutions and aggressively establish competitive product offerings.”

Yves Le Pottier – Electrical Device Supplier

“I cannot leave a discussion of Enventive without mentioning it is fun to use. The software is graphically based. Sketches and graphical representations of the parts drive the models. This, coupled with the easy to use interface, creates “Stack-up Junkies” who want to do the analysis because the software helps them easily visualize the impact a design change can have on the product.”

Eric Pattok – Delphi Steering Systems

“Our engineering team has been able to use Enventive after 4 days of training. We have been able to correct some design mistakes that were done in the past due to the limitations of the tools we were using. In the end, our customer praised us for the speed and professionalism with which we have been able to complete and present the DFSS phase on this project.”

Pedro Lopes – Ficosa International

ENVENTIVE WILL OPTIMIZE YOUR PARAMETERS!

Optimizing Parameters

Documents

Transcript of Optimizing Parameters