Topology Optimization of Racecar Suspension Uprightsluxonengineering.com/pdf/altair_htc_2011.pdf ·...

Copyright © 2011 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.

Topology Optimization of Racecar Suspension Uprights

Billy Wight

Luxon Engineering

Altair HyperWorks Technology Conference

June 23, 2011

Orlando, Florida


6/23/2011

Slide 2

Company Profile

y = 639.26xR² = 0.9955

y = 6.2275x + 461.61R² = 0.9901

y = 278.39x - 1278.4R² = 0.9997

y = 6.9865x3 - 255.27x2 + 3119.1x - 11266R² = 0.9994

y = 4.6277x + 220.62R² = 0.496

0

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0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00

Tru

e St

ress

(M

Pa)

True Strain (%)

NiTiNOL, Af = 19 CAustenite Phase E

Pseudoelastic Austenite toMartensiteMartensite Phase E

Plastic Deformation

Pseudoelastic Martensite toAusteniteLinear (Austenite Phase E)

• San Diego Based Engineering Consulting Firm • Product Development

• Mechanical Design and Analysis

• Finite Element Analysis/Optimization

• CAD Modeling and Manufacturing Drawings

• Located in San Diego, California

• Small Company, 3 Engineers on Staff

• In Business Since January, 2007

• Wide Variety of Industries Served • Industrial Equipment

• Medical Device

• Consumer Products

• Automotive


6/23/2011

Slide 3

Application Profile

F1000 (Formula B) Class

• Open Wheel

• Stock 1000cc Motorcycle Engine

• 1000 lbs Minimum Weight

• 155 mph Max Speed

• ~ 1200 lbs Downforce @ 155 mph

• 2.4 g’s Lateral Acceleration

• Base Price $39,900 (Roller, No Engine)

D Sports Racer (DSR) Class

• Closed Wheel

• Modified 1000cc Motorcycle Engine

• 900 lbs Minimum Weight

• 165 mph Max Speed

• ~ 2000 lbs Downforce @ 165 mph

• 2.8 g’s Lateral Acceleration

• Base Price $59,900 (Roller, No Engine)


6/23/2011

Slide 4

Previous Application Project

Modified Salisbury Differential • Collaborative Effort Between Luxon Engineering and Williams Racing Developments (WRD)

• Chain Drive from 1000cc Motorcycle Engine

• Direct Replacement for Stohr Cars

• Fits Other Manufacturers

• Speeds, Phoenix, Radical, etc.

• Substantial Weight Savings and Performance Benefits vs. Stock


6/23/2011

Slide 5

Design Challenge: Suspension Uprights

• Simple, Inexpensive

• Multi-Piece (Bolt-on Brackets)

• Designed to “Get the Job Done” at an Inexpensive Price Point

• Necessary to Maintain a Reasonable Price for the Base Car

(front) (rear)

Stock Stohr Uprights (Current Design)


6/23/2011

Slide 6

Design Goals and Constraints

Performance Goals:

• Light Weight - Minimize Unsprung Mass

• High Stiffness - Minimize Compliance

• Suspension Compliance =

• One Piece Design – Remove Failure Modes

Design Constraints:

• 6061-T6 Material

• Readily Available

• Low Cost

• Good Strength to Weight Ratio

• 3-Axis CNC Manufacturing

• Readily Available

• Reasonably Priced

• Keep Stresses Low, ≤ 160 MPa for Main Loadcases

? What is the most

efficient method of

achieving our goals

subject to the design

constraints?

( , )f Springs Dampers


6/23/2011

Slide 7

Altair Analysis Solutions

16 Different Loadcases

• 5 Main Loadcases

• Typical Racing Environment

• 11 Additional Loadcases

• Bump Loading, Off Track Loading, etc.

• Derived from:

• Vehicle Datalog Measurements

• Suspension Kinematics

• Tyre Data

• Aerodynamic Data

Meet Design Goals Satisfying Constraints

• Minimize Design Iterations

• Decrease CAD Modeling Time

• Decrease Analysis Setup Time

• Engineering Time = $$$

• Decrease Product Development Time

• Introduce Product to Market ASAP

TOPOLOGY OPTIMIZATION

• Supports Multiple Loadcases • One Analysis Run Reveals Optimum Load-Paths

• Stress Constraint • Manufacturing Constraints


6/23/2011

Slide 8

Loadcase Development

• Accurate and Complete Loadcases are of Vital Importance

• Optimization Algorithm Can Only Optimize to the Inputs it is Given

• Vehicle Data Logging

• Allows for Accurate Loadcase Determinations

• Verification of Calculations and Assumptions

• Extensive/Thorough Calculations

• Account for All Possible Load Conditions

• Thermal Effects, etc.

0 0 3512 0 0 3512

-2051 0 2578 -3537 0 4446

3537 0 4446 2051 0 2578

0 -3853 4342 0 -3853 4342

0 0 3226 0 0 3226

Bump Acceleration Direction (-X) (+X) (-Y) (+Z) Bump Acceleration Direction (-X) (+X) (-Y) (+Z)

Steady State Bump -269 269 -1612 7249 Steady State Bump -269 269 -1612 7249

Bump During Left Corner -2248 -1854 -1183 2578 Bump During Left Corner -3877 -3197 -2041 11919

Bump During Right Corner 3197 3877 -2041 11919 Bump During Right Corner 1854 2248 -1183 2578

Bump During Braking -332 332 -5846 11398 Bump During Braking -332 332 -5846 11398

Bump During Acceleration -247 247 -1481 5818 Bump During Acceleration -247 247 -1481 5818

0 0 4120 0 0 4120

-2163 0 2719 -4392 0 5521

4392 0 5521 2163 0 2719

0 -2920 3290 0 -2920 3290

0 2335 4406 0 2335 4406

Bump Acceleration Direction (-X) (+X) (-Y) (+Z) Bump Acceleration Direction (-X) (+X) (-Y) (+Z)

Steady State Bump -315 315 -1891 9725 Steady State Bump -315 315 -1891 9725

Bump During Left Corner -2371 -1955 -1248 2719 Bump During Left Corner -4815 -3970 -2534 16731

Bump During Right Corner 3970 4815 -2534 16731 Bump During Right Corner 1955 2371 -1248 2719

Bump During Braking -252 252 -4430 5576 Bump During Braking -252 252 -4430 5576

Bump During Acceleration -337 337 313 11155 Bump During Acceleration -337 337 313 11155

Tyre Contact Patch Forces: 2010 Stohr WF1

Right Front Tyre Contact Patch Forces (Newtons)Left Front Tyre Contact Patch Forces (Newtons)

Steady State

Left Corner

Steady State

Left Corner

Right Corner

Braking

Right Rear Tyre Contact Patch Forces (Newtons)

Right Corner

Braking

Accelerating

Braking

Accelerating

Right Corner

Braking

Right Corner

Left Rear Tyre Contact Patch Forces (Newtons)

Left Corner

Steady State

Accelerating Accelerating

Steady State

Left Corner


6/23/2011

Slide 9

Topology Optimization: Parameters, Front

3- Axis CNC Manufacturing

Split (Both Sides) Draw Direction Constraint

• Ensures No Undercutting in the Result

Multiple Loadcases

Stress Constraint, 100 MPa

• Weights Each Loadcase Equally

• Maintains Target Stress Levels

Minimize Unsprung Weight

Optimization Goal: Minimize Mass


6/23/2011

Slide 10

Topology Optimization: Solution Sequence, Front

TET4 Design

Space (Yellow)

“Material that

CAN be there”

Topology Result

“Material that

NEEDS to be there”

CAD

Interpretation

Final Design

TET10 Analysis

Model Iterate


6/23/2011

Slide 11

Topology Optimization: Parameters, Rear

3- Axis CNC Manufacturing

Split (Both Sides) Draw Direction Constraint

• Ensures No Undercutting in the Result

Decrease Cost

Symmetry Constraint

• Ensures Symmetry in the Result

• Rear Uprights are the Same Part Left/Right

Multiple Loadcases

Stress Constraint, 100 MPa

• Weights Each Loadcase Equally

• Maintains Target Stress Levels

Minimize Unsprung Weight

Optimization Goal: Minimize Mass


6/23/2011

Slide 12

Topology Optimization: Solution Sequence, Rear

TET4 Design

Space (Yellow)

“Material that

CAN be there”

Topology Result

“Material that

NEEDS to be there”

CAD

Interpretation

Final Design TET10 Analysis

Model

Iterate


6/23/2011

Slide 13

Performance Results

Mass – Decrease of 40%

• ~ 1.5 lbs per wheel

Stiffness – Increase of 225%

• Measured via Deformation of a Node at the Tyre Contact Patch

Stress – Goals Achieved

• Stress < 160 MPa (Main Loadcases)

• Stress < 220 MPa (All Loadcases)


6/23/2011

Slide 14

Conclusions

Engineering Time = $$$

• Optimization Eliminates the Multiple

Iterations of Traditional FEA • Typical Problems Would Have Taken

15+ Iterations

• The Optimized Design is Often Non-

Intuitive • Unlikely that Traditional Techniques

Would Yield the Same Result

Altair Optistruct Substantially Reduces

Engineering Overhead and Development Time


6/23/2011

Slide 15

Questions, Comments?

Billy Wight

President

Luxon Engineering (858) [email protected] www.luxonengineering.com

J.R. Osborne, 2008 SCCA DSR and CSR National Champion

Topology Optimization of Racecar Suspension Uprightsluxonengineering.com/pdf/altair_htc_2011.pdf ·...

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