Carbon Fiber Parts Performance In Crash SITUATIONS - CAN WE PREDICT IT?

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1 Carbon Fiber Parts Performance In Crash SITUATIONS - CAN WE PREDICT IT? Commercial Division of Plasan Sasa 2016 by Plasan 1

2 ABOUT THE AUTHORS D.Sc - Technion - Israel Institute of technology Head of the simulation and survivability team, Plasan Specialities: High strain rate dynamic simulation- Crash, Blast, Penetration FE Analysis, Discrete Element simulation, Multi body Simulations Soil Dynamics Mechanics of materials Dr Zvika Asaf Dr Vadim Favorksy PhD Ben Gurion University of the Negev Senior R&D engineer, Plasan 2016 by Plasan 2

3 ABOUT PLASAN World s leading designer and supplier of lightweight composite/ metal-composite vehicle bodies 2016 by Plasan 3

4 ABOUT PLASAN International company with R&D and manufacturing facilities in Israel, US, and France plus broader partner network 2016 by Plasan 4

5 THE PROBLEM Design with composite in elastic regime is well known and understood But what happens After failure? Crash High rate dynamic phenomena milliseconds 2016 by Plasan 5

6 THE MODEL PLASAN EXPERIENCE WITH HIGH RATE DYNAMIC BLAST STRUCTURE INTERACTION BLAST TEST A mine blast is essentially the same as a crash impact, just from underneath Hybrid III dummies Simulation calibrated by physical testing 2016 by Plasan 6

7 COMPOSITE MATERIALS IN MINE BLAST CONVERTING STEEL CAB TO COMPOSITE CAB SIMULATION RESULTS WITH STEEL DEFLECTOR Steel Cab 586 kg E-glass Cab 260 kg E-glass with Aluminium frame Cab 280 kg 2016 by Plasan 7

8 E-GLASS MODEL CALIBRATION THE DESIGN Properties verification MTS tension test Very different from behaviour of metals Anisotropic material Properties in one direction not necessarily shared in others Many variables (fibre, orientation, resin, production process) FE model at level of fibres Interlaminar relationships Modes of failure 2016 by Plasan 8

9 LAMINATED COMPOSITE - FAILURE IN BENDING The delamination process 2016 by Plasan 9

10 E-GLASS BALSA-WOOD STRUCTURE 3-POINT BENDING, 100 MM/SEC SIMULATION TEST CONTACT FORCE COMPARISON 2016 by Plasan 10

11 E-GLASS WITH ALUMINIUM FRAME CAB BLAST TEST RESULTS COMPOSITE CABIN POST BLAST 2016 by Plasan 11

12 E-GLASS WITH BALSA CAB BLAST TEST RESULTS COMPOSITE CABIN POST BLAST 2016 by Plasan 12

13 MODELING LAMINATED COMPOSITE AGAINST BALLISTIC THREAT SIMULATION TEST First shot Second shot FRONT VIEW PROJECTILE 2016 by Plasan 13

14 CARBON COMPOSITES CRASH MODELING Velocity [m/s] Force [kn] Braking Forces N Displacement [1E-3m] Steady state forces N 2016 by Plasan 14

15 THREE POINT BENDING DROP TEST Force [kn] Middle Crack 2016 by Plasan 15

16 DESIGN OPTIMISATION FLOWCHART Problem Definition (Materials, Manufacturing Constraints etc.) Topological Optimisation (Static, OptiStruct ) Thickness Optimisation (Static, OptiStruct ) Optimisation Parameters Tuning No Validation of the results (Dynamic, LS-DYNA ) Satisfying results Yes Optimisation Parameters Tuning No Satisfying results Validation of the results (Dynamic, LS-DYNA ) Angles Optimisation (Static, OptiStruct ) Yes Fine Tuning (Dynamic, LS-DYNA ) Satisfying results No Parameters Tuning Yes End 2016 by Plasan 16

17 TOPOLOGICAL OPTIMISATION THE MODEL The Optimisation was performed with OptiStruct 2016 by Plasan 17

18 TOPOLOGICAL OPTIMISATION LOAD CASES Distributed Force Fixed Boundary Load Y Load Y 2016 by Plasan 18

19 TOPOLOGICAL OPTIMISATION RESULTS 2016 by Plasan 19

20 LAYUP AND ANGLE OPTIMISATION 11 Visualisation of the Walls Thicknesses The beam was divided into 13 regions (see the figure). Each region was built from 4 sub-plies having [0/45/90/- 45] lay-up First Path The optimisation variables in this stage were the thicknesses of the sub-plies (13*4 variables) 2016 by Plasan 20

21 OPTIMISATION FOR MANUFACTURING AND COST CONSTRAINTS Visualisation of the Walls Thicknesses 1 2 The beam was divided into 2 regions (see the figure). Each region was built from 4 sub-plies 2016 by Plasan 21

22 PLASAN MODEL AFTER OPTIMISATION RESULTS Material: Aluminium Mass: 11.2 Material: UD Carbon Mass: 8.0 kg (34% reduction) Fmax 75 kn; Ref. Fmax 47 kn; 2016 by Plasan 22

23 Applied Force, kn COMPARISON BETWEEN DESIGNS Reference Aluminum Design Carbon Plasan Energy Absorbed: Reference Aluminium (12.2kg): 6.3kJ Plasan Carbon (8.0kg): 10.2 kj Displacement, mm 2016 by Plasan 23

24 FULL COMPOSITE FRAME SCHEMATIC VIEW FOR ILLUSTRATIVE PURPOSES ONLY 2016 by Plasan 24

25 OVERVIEW OF THE NUMERICAL MODEL COMPOSITE BEAMS COMPOSITE SKINS ALUMINIUM CONNECTIONS 2016 by Plasan 25

26 ROOF CRUSH FMVSS 216 Local buckling: F = 8 40mm Global buckling: F = 9 60mm 2016 by Plasan 26

27 Side pole crash test is detailed in FMVSS 214. The car is moving at 20 MPH on a line passing through the driver head COG, at 75 from the longitudinal centreline. The crash is between the car and a rigid pole of Ø10 SIDE POLE IMPACT - FMVSS by Plasan 27

28 RESULTS OF THE ANALYSIS The frame absorbed the crash energy without penetration into the occupants volume 2016 by Plasan 28

29 FRONTAL IMPACT - FEA VIDEO Frontal Crash force 2016 by Plasan 29

30 CONCLUSIONS Composite crash is predictable Potential 30% weight saving to aluminium Basic design concepts must be changed FEA is part of design for cost process 2016 by Plasan 30

31 THANK YOU by by Plasan 31