Solorean Suspension Team The University of Texas at Austin Mechanical Engineering Design Project

1. Solorean Suspension TeamThe University of Texas at AustinMechanical Engineering Design Project Prepared by: Paul Clemmons Tiana Cradduck Randy McCoy Nick Wymore Submitted to: Dr. Crawford TA: Dennis Liu

2. Outline • Background of project • Problem statement • Requirements • Constraints • Deliverables • Methodology

3. Background • Sponsor: Longhorn Solar Race Car Team – Dr. Hallock (ECE) & Geoff Grimes (M.E.) • Project: Design of Solarean’s suspension for the North American Solar Challenge 2008 • North American Solar Challenge 2008 is a solar car race to increase awareness of renewable energy sources • Length of the race is approximately 2500 miles

4. Problem Statement • To design a suspension that is light weight and provides adequate performance, as well as satisfy any pertinent regulations.

5. Requirements • Design the suspension components for a solar car • Integrate mounting components onto chassis for two independent braking systems • Possess parameters for OTS parts capable of meeting environmental demands for solar car • Use the chassis design provided

6. Solorean Chassis Design UT Solar Team

7. Constraints • Geometric • 2 Front wheels, 1 back wheel • Motor placement in rear • Maintain current chassis design • Wheelbase length = 100 in • Ground clearance when fully loaded = 9 in

8. Constraints (cont.) • Kinematics • Car velocity <= 60 mph • Max radius of turn = 6 m • Minimum braking deceleration = 10.56 mph/s • Forces • Max weight of suspension = 50 lbs • Capable of the following: 1G turn, 1G bump, and 1G turn with 1G bump

9. Constraints (cont.) • Material • Chromolly steel or aluminum used • Production • Components machined in four or five steps • Safety • No part interference while turning • Suspension components must withstand a 2500 mile race, 10000 lifetime

10. Deliverables • Engineering drawings for all suspension components specified • FEA analysis of all designed parts • Specifications for off the shelf parts • Complete Bill of Materials

11. Methodology How? When? What?

12. How? 1.) Research 2.) Design Selection 3.) Finite Element Analysis 4.) Analytical Calculation 5.) Dynamic Simulation 6.) Final Design 7.) Bill of Materials

13. When?

14. What?

15. Research and Preliminary Design • Research: - solar cars - competitive cars - motorcycles • Create four designs, including the previous design (Solar Steer)

16. Design Selection • Create a Pugh Chart using the four concepts generated from research • Use Pugh Chart to determine the best concept design

17. Finite Element Analysis (FEA) • Create part to scale in SolidWorks • Preliminary force analysis using COSMOSWorks • Dynamic Forces: - 120% Front - 80% Back

18. Analytical Calculations • Spring Rates • Damping Rates • Stopping Force • Brake Disc Size

19. Dynamic Simulation • Verify Analytical Calculations • 1G Bump Test • Front and Rear Parameters will be different

20. Final Designs • Based on: 1.) Pugh Chart 2.) Finite Element Analysis 3.) Analytical Calculation 4.) Dynamic Simulation • Analysis may create changes in the original design

21. Bill of Materials • OTS parts • Stock material needed for fabrication • Fasteners

22. Methodology 1.) Research 2.) Design Selection 3.) Finite Element Analysis 4.) Analytical Calculation 5.) Dynamic Simulation 6.) Final Design 7.) Bill of Materials

23. Questions?