The thermostamping process of thermoplastic composites can be analyzed with simulation software. In addition to the optimization that can be brought to process (defects, raw material quantity …), the main interest is to integrate results from process into the performance simulation. This article presents an approach to simulate thermostamping of thermoplastic composites (PA) with HyperForm. The material law is identified from Bias test trials, then, the simulation is performed by HyperForm with the solver Radioss or Ls-Dyna. Fiber orientations (for non-linear anisotropic behavior) and defects (global wrinkles, and wrinkles in the thickness, area with failure risk, thickness variation…) are identified and mapped on structural mesh for mechanical simulation. Based on this approach, several test/simulation comparisons were performed on both static and dynamic. They demonstrate the necessity of considering the process phase, especially for complex geometries. Regarding advanced application for such simulation tool: Faurecia Automotive Exterior is developing technologies to produce one-shot visible parts (CFRT thermostamping + overmolding injection in one step). This case study is the most challenging application we are working on. Combining thermostamping simulation and one-shot process brings benefits to both sides thanks to cross results on complex application. Globaly, to improve the prediction of this simulation tool, next steps are the computation of local density; the consideration of thermal exchanges with the mold during the production process; the modelization improvement of boundary conditions during process (woven holding …, frames…). Speakers Guillaume CHAMBON, Product Research & Advanced Simulation Manager, FAURECIA Automotive Exterior

1. EATC 2015: Composite Thermoforming Calculation
G. CHAMBON, R. TIE BI
October 1rst, 2015

2.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
2

3.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
3

4. 4
Leader in automotive equipment
* of which €14.1 billion of product sales
34
countries
99,500
employees
330
sites
€18.8
billion of total sales*
6,000
engineers and technicians
30
R&D centers
515
programs in development
505
patents filed in 2014

5. 5
Faurecia Automotive Exteriors
Plastic body parts
Modules
Composite
 Bumpers
 Trims & Rocker Panels
 Outside Body Panels
 A-class
 Semi-Structural
 Structural
€1.7 billion
product sales 2014
8,100
employees
employees
32
production sites
4
R&D centers
9
countries
#1 in Europe for plastic body parts
 Front End Modules
 Front End Carriers
 Engine Cooling Systems

6.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
6

7. 7
Continuous Fiber Reinforced Thermoplastic Thermostamping
Composite
What is it ?
CAD of part Sheet of CFRT Heating of CFRT (hoven)
Manufactured part Transfer and Stamping
170 mm

8.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
8

9. State of the art: Based on commercial codes
Codes 
HyperForm one
step
PamForm Catia
Mainproperties
Reverse
engineering
  (grid projection) (grid projection)
Basic strain
calculation
  (only shear)  (only shear)
Locking angle   
- Initial assessment of formability of a component
- Preform and fiber architecture predictions (reduction of raw material waste)
- Highligthing possible forming problems (locking and wrinkage, aspect…)
9
 2 families of codes
1/ Non incremental Codes

10. State of the art: Based on commercial codes
Codes  Ls-Dyna incremental Radioss incremental
Mainproperties
suitable and complete GUI  
suitable post-analyse and mapping GUI  
suitable multi layers approach  
thermomechanical coupling  
suitable constitituve laws   (less than LS-Dyna)
Die outer
element
Die
Punch
Blank
Binder
 2 families of codes identified according to incremental calculation or not
2/ Incremental Codes
- realistic forming approach with dynamic non-linear explicit codes
- forming pressure modelized w/ contact properties for die & punch
- if necessary, boundary or/and initial conditions modelized
- suitable approach for material laws
10

11.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
11

12. Thermostamping constitutive laws
Radioss: Mat 58 with Prop 16. Fiber behavior
Ls-DYNA Mat 34 (bending effect compared to Mat 234)
12
BIAS Test
Mat 58 (Radioss) and Mat 34 (LS-DYNA) are quit equivalent and realistics
(without thermomechnical effect)
 Radioss / LS-Dyna comparison

13. X-ray
Calcination
Samples level : Tests performed to identify Behavior of woven
Process simulation at sub-system level
Simple part level : Tests performed to establish simulation procedure
Sub-system level on FAE representative mold
Microscope
FromsamplestoSub-System
Correlation of fiber orientation to improve
representativeness of mechanical simulation
Thermostamping constitutive laws
Building processus

14.  Multi-layers approach to represent discriminating defects
Left 100 mm Right 25 mm Right 0 mm Right 100 mm
Thermostamping constitutive laws
Results & Correlation
14

15. Thermostamping constitutive laws
Results & Correlation : Step by step
Production of uncompleted
parts for step by step
correlation with simulation
Shapes and fiber’s
orientation comparison
15

16.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
16

17. Fiber’s orientations post-analyzed and mapped by Hypercrash
Test component
Mapped results
17

18. Structural law considering non-orthogonal angles
+
UD2
Fabric material
decomposition
in 2 UDs
Qij = f(Eij, ij, (k=1,2)) identified by reverse
Engineering
 ≠90°
18
 Reverse Engineering initialization
 Axial modulus: Qij (UD) = Qij (Fabric)
 Transverse modulus : Qij (UD) = Qij (Matrix)
 Shearing: Qij (UD) = Qij(Fabric)/2
UD1
1 2
 FAE approach

19. Structural law considering non-orthogonal angles
- Linear elasticity
- Non-linear damage
- Failure
 Elasticity, damage and failure properties of the 2 UDs are re-identified by reverse
Engineering method from specimen and sub-system tests
specimen tests (dynamic tensile,
compression and shear)
sub-system test (dynamic bending)
LS-DYNA material law 58
19

20.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
20

21. Part
Effort
Failure
High stamping
spare wheel box
Structural law
Results & Correlation : Static tests
Good accuracy, including failure representation

22. Config. FLAT Config. Spare Wheel Box
Structural law
Results & Correlation : Dynamic tests
Trial
Trial
Simulation w/o process consideration
Simulation w process simulation
Important improvement regarding flat conf. confirming process influence
Need to enhance SWB conf. models

23.  Company presentation
 What is thermostamping ?
 State of the Art
 Thermostamping constitutive laws
 Characterization / identification
 Validation
 Mapping
 Transfer from process results to performance meshing
 Structural law creation
 Performance simulation : Results & correlation
 Synthesis - Next steps
Agenda
23

24. Synthesis
 Mandatory to consider thermostamping process for performance simulation of
complex parts
 Necessity to use incremental calculation (i-o geometrical) for good accuracy on
singularities (sliding, locking angle, wrinkles …)
 Need to have a good characterization of material (Product & Process)
 Need to simulate individual behavior of each ply stacked (multi-layer or other
approach)
 Simulation tool compatible with daily engineering

25. Next steps :
Modelization of thermal effect
Coolingvelocity(°C/s)
From 0 to 30 seconds
Air
Contact plate/mold From 30 to 60 seconds
25
 Cooling down velocities depending on time and contact nature
Quick T° drop, with influence on
material behavior, especially in mold

26. Die
Part of binder
Punch
Blank CFRT
Binder
26
Next steps :
Boundary and initial conditions effect
 Considering frame or any means used for processing material (frame, blank holders…)

27. Next steps :
software
 Enhanced thickness variation
 Thermomechanical effect (Radioss incremental)
 Fiber density computation (Hyperform)
 Non-orthogonal angles elements for performance simulation

28. NEXT STEP FAE
Innovative Application : One-Shot Process for composite
Liftgate
:
28
State of the art: Structural parts (non visible)
Innovation: Structural and aspect parts
Overmolded
composite
inserts
CFRT positionning in mold
Infra Red heatingCFRT blanks
Robot handling from hooven to mold,
Draping + injection
Injection over-molding
Gripper: pre-forming
Aspect surface
Challenges:
 Complete overmolding of three composite inserts
 Delivery of a high-quality surface with graining
Visible side
Back side

29. 29
NEXT STEP FAE
Innovative Application : One-Shot Process for composite