CAE Design approach to develop applicative solutions in automotive polymer based systems

1. First Southern European Technology Conference CAE Design approach to develop applicative solutions in automotive polymer based systems M. Chiara Ferrari, Filippo Gallieri Montecarlo, June 7-9 2000

2. DESIGN & CAE Business Support Tool to develop applicative solutions in automotive polymer based systems

3. Design & CAE: a powerful tool in the Business Support Computer Aided Engineering Testing & validation Design

4. CAE TOOLS Product actual service conditions main variables/part performances Simulation computer calculation replacing qualitative/empirical approach Process tools and conditions process influence on part

5. New material/processes Design solutions CAE ADVANTAGES Production Process Tests (homologation ...)

6. CAE ADVANTAGES • New material/processes: • - no process tool building during the preliminary evaluation phase • - critical issues investigated by simulation • Design solutions: • - no prototype building up • - several solutions evaluated and compared in short time: • - materials • - mechanical constraints • - geometry

7. CAE ADVANTAGES • Tests (homologation ...): - the number is dramatically reduced; - main tests are focused on the final solution; - possible flops are predicted and solved on the computer • Production Process: • - avoiding tools judged inadequate once already set up • - part quality: - part performances foreseen in the design phase are respected - controlled defects due to process • - time/costs are optimised

8. CAE & MONTELL • Supporting to Montell product development • - property profile for specific applications • - directions for improvement • Driving the customer to Montell materials • - advanced properties • - best material/design system • Establishing Montell as a leading supplier • to the technical industry: • - differentiated offering • (product and service)

9. Internal: • new material/application development • External: • penetration into the market R & D CAE: A KEY FACTOR FOR Business

10. Car dashboards: from new concepts to first applicative projects

11. New concepts on dashboards OBJECTIVE: cost reduction Computer simulation in the early feasibility stage to compare solutions (materials, design, thickness) Dashboard system complexity causes a big influence of design (shape, assembly solutions) on final performances.

12. New concepts on dashboards: creep as a key issue Cycle: heating to 85°C, 22 hours creep, cooling to 23°C Example of Z displacement distribution after 22 hours creep at 85°C and cooling to room temperature example: Renault X76 customer: Allibert

13. New concepts on dashboards: creep as a key issue Cycle: heating to 85°C, 22 hours creep, cooling to 23°C Displacement comparison of selected points Material BR131G BR131G CR250F CR1152F Density 1.14 1.14 1.04 0.97 Thickness of the dashboard 2.8 2.4 2.8 2.8 Upper right corner 0.85 0.79 1.25 2.25 of central console Top of instrument cover 1.21 1.08 1.27 1.73 (“visière”) Bottom of glove box 2.35 2.43 2.43 2.45 Local relative displacement 0.70 0.90 0.36 0.56 in right horizontal area

14. STRATEGY: concurrent engineering and simulation based design offered to selected partners

15. Montell Design Support: • - Static behaviour • - Long term thermal stability (thermal/creep simulations) • - Head impact simulation (ECE R 21 Standard) • - Dynamic behaviour (Vibration) • - Moldfilling simulation for all dashboard components • Applicative project for dashboard development grades

16. Part performances (static, thermal/creep, head impact, vibration) main phases : • Preliminary feasibility calculation with simplified assumptions: highlight of general behaviour, does it work? • Detailed calculation: - problem solving and optimisation on single components • - evaluation of different material solutions • Rework of design according to CAE guidelines (customer) • Possible last calculation on final design

17. Dashboard: Head impact ECE R 21 IMPACT POSITIONS

18. Dashboard: Head impact ECE R 21 Fig 18

19. Dashboard: Thermal cycle AF 6 H 85C 16 H 40C 3 H

20. Dashboard: Thermal cycle AF

21. Dashboard: Thermal cycle AF

22. Dashboard Component: Manufacturing process design

23. Dashboard : Manufacturing process design • Process simulation: main phases • Preliminary calculation: - choice of best manufacturing process (injection molding?, traditional? sequential?) - evaluation of different materials - evaluation of different gating solutions • Final calculation: - runner system balancing - investigation on process parameters influence (packing) • Special calculations for critical parts (injection molding): - cooling - warpage

24. Dashboard: Manufacturing process design Coiffe & runner system finite element model 1

25. Dashboard: Manufacturing process design Runner system dimensions [mm] Cold sprues G1 , G3 , G4 , G5 , G6 Ø= 6 to 10 Cold runners G1 , G3 , G4 , G5 , G6Ø= 10 G5 G4 Ø= 24-8 Ø= 20-8 G6 G1 Ø= 20 G3 Ø= 24-8 G2 Ø= 20 Ø= 20-8 Ø= 20 i)Ø= 16 ii)Ø= 20 i)Ø= 14-6 ii)Ø= 22-8 Ø= 20-8 G2 , Cold sprue Ø= 5 to 8 G2 , Cold runner Ø= 8 G1 , G2 , G3 , G5 , G6 Gates (width x length x tk) thin area 20 x 2 x 1.8 thick area 20-0 x 8 x 8 G4 Gate (width x length x tk) thin area 120 x 2 x 1.8 thick area 120 x 8 x 8 This is the only difference between type i) and type ii)

26. Ddashboard: Manufacturing process design Molding machine parameters & Variable limits for PP Mold temperature Clamp force 40 deg.C 1300 Tonne Max. Pressure No Restraints Variable limits for PP: Max. Pressure = 90100 MPa Max shear stress = 0.25 MPa Max. shear rate = 100000 1/s Melt temperature 250 deg.C Fill time 6-8 sec

27. Ddashboard: Manufacturing process design Fill time [s] & Weld lines

28. Dashboard: Manufacturing process design Pressure at end of filling [MPa]

29. Dashboard: Manufacturing process design Clamp force trend [Tonne] Max value = 740 Tonne

30. Dashboard: Manufacturing process design

31. HSBM Thin wall bumper concept CAE support to concept development Evaluation of thickness reduction feasibility and design optimization Structural performances Molding technology e.g. sequential injection e.g. thermal/creep behaviour CAE simulations as a key issue

32. Thermal/creep cycle simulation on bumpers • Temporary dilatation due to CLTE • Possible permanent deformations • due to dilatation and weight High temperature effect To allow evaluation of material behaviour and design changes effect: • Simulation of the whole cycle (heating, creep, cooling) • Material nonlinearities considered (CLTE vs. temperature, • stress/strain vs. temperature, creep vs. time, temp., stress) • Temperature distribution: constant (e.g.oven) or variable • along the surface and across thickness (e.g. sunload effect)

33. Thermal/creep cycle simulation on bumpers Local temporary deformation during high temperature cycle

34. Thermal/creep cycle simulation on bumpers Local final deformation after high temperature cycle and cooling

35. CAE: A KEY FACTOR FOR MONTELL CUSTOMER WORLD MONTELL DESIGN & CAE WORLD Design Idea Preliminary Design IN Static Impact Thermal ! Creep MATERIAL CHOICE Prototype DEVELOPMENT Fatigue Flops SIMULATION Vibration IMPROVEMENTS PROBLEM SOLVING PRODUCTION Injection molding New material OUT Gas-assisted inj. Molding FINAL DESIGN MARKET Thermoforming Extrusion Blow molding