1. Redesign of Lotus Europa Front Suspension ME 450: Finite Element Analysis Spring 2007 Presented by: Bart Sudhoff, Zachary Lightner, Jim Milligan, Brian Schludecker, David Giles Dr. Nema 4/30/2007

2. Summary & Introduction Redesign Front Suspension Upper Control Arm Redesign Front Suspension Upper Control Arm Top Speed Increase: 120 to 200 MPH Top Speed Increase: 120 to 200 MPH Design Issues: Design Issues: New weight of car due to increased engine size New weight of car due to increased engine size New handling characteristics New handling characteristics

3. Original Design Built in 1970 Built in 1970 1470cc OHV 4 Cylinder Engine – 78HP 1470cc OHV 4 Cylinder Engine – 78HP Front Wheel Drive Front Wheel Drive 4-Speed Transmission 4-Speed Transmission Curb Weight: 1320- 1570lbs Curb Weight: 1320- 1570lbs Top Speed 120 MPH Top Speed 120 MPH

4. New Design Engine: Lexus V8 4.0L Quad Cam Engine: Lexus V8 4.0L Quad Cam Transmission: Porsche 5-Speed Transmission: Porsche 5-Speed Suspension: New Design of Lower/Upper Control Arms, Springs, Shocks Suspension: New Design of Lower/Upper Control Arms, Springs, Shocks Factor of Safety of 5 Factor of Safety of 5 Light Weight Light Weight Minimal Deformation Minimal Deformation

5. Theoretical Background Decomposition of model into stiffness, force matrices Decomposition of model into stiffness, force matrices Solution in form of nodal displacement matrix Solution in form of nodal displacement matrix 4-node tetrahedral element displacement solution 4-node tetrahedral element displacement solution

6. Model Details Upper and Lower Control arms modeled using Pro/E Upper and Lower Control arms modeled using Pro/E Constraints Constraints Fix – about the mounting holes Fix – about the mounting holes Forces applied at ball joint Forces applied at ball joint

7. Model Details

8. Load Case:XYZ Vertical Bump0g 3g0g Rebound0g 2g0g Pothole0g 4g1.5g Force (N) Load Case:XYZ Vertical Bump0-1024.5 -3166.3 Rebound06832110.9 Pothole-4221.8-1366-768.3

9. Model Details

10. Results 2” thick arm 2” thick arm Stress - 20.06 MPa Stress - 20.06 MPa Deformation -.102 mm Deformation -.102 mm Safety Factor – Greater than 10 Safety Factor – Greater than 10

12. Results 1.75” thick arm 1.75” thick arm Stress - 25.1 MPa Stress - 25.1 MPa Deformation -.128 mm Deformation -.128 mm Safety Factor – Greater than 5 Safety Factor – Greater than 5

14. Results 1.75” thick arm with relief 1.75” thick arm with relief Stress - 18.9 MPa. Stress - 18.9 MPa. Deformation -.131 mm Deformation -.131 mm Safety Factor – Greater than 5 Safety Factor – Greater than 5

16. Results 1.5” thick arm with relief 1.5” thick arm with relief Stress - 24.4 MPa Stress - 24.4 MPa Deformation -.184 mm Deformation -.184 mm Safety Factor – Greater than 5 Safety Factor – Greater than 5

18. Results 1.5” thick arm with relief 1.5” thick arm with relief Vertical Bump Vertical Bump Stress - 3.82 MPa Stress - 3.82 MPa Deformation -.0229mm Deformation -.0229mm Safety Factor – Greater than 10 Safety Factor – Greater than 10 Rebound Rebound Stress - 14 MPa Stress - 14 MPa Deformation -.106mm. Deformation -.106mm. Safety Factor – Greater than 10 Safety Factor – Greater than 10

21. Conclusion Chose 1 ½” control arm with relief cuts Chose 1 ½” control arm with relief cuts Passed factor of safety tests Passed factor of safety tests has allowable deformation has allowable deformation Will allow car to go 200 mph Will allow car to go 200 mph