ALTAIR Composites Forming Activities 2014

Innovation Intelligence®

Thursday, April 3rd

Erwan Beauchesne, Vincent Diviné …

Composite Forming Activities

Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.

Introduction/Context

UD and woven fabric modeling

B-Pillar model example

Hyperform updates

Mapping

Meso to macro multiscale approach

Draping

Conclusion


Introduction/Context/History

• Simple set up with reduced numbers of input data

• Accurate enough to give main tendencies

• Fast enough to be used in an industrial context

1) To provide a simple solution which gives tendencies

2) Seamless crash model initialization with forming results

Batch mode

Manufacturing

+

Mapping


2010 First meeting with Solvay which was looking for a stamping simulation

tool able to manage their material laws coming from Digimat

2012 January we got a benchmark from Solvay about composite forming

June 13th and 14th Solvay presented our results at the SFIP conference

April 2013 Solvay presented coupling in composite crash simulation at ATC

in Turino

2012 Cedrem contacted us to exchange with us their experience

with mesoscopic approach using Radioss and to discuss about mapping.

May 25th 2012 presentation with Cedrem at DynaComp conference in France

History


History

2012 September : thanks to Solvay presentation at SFIP Conference, PO

asked us to present them our works

2012 September : thanks to Solvay presentation at SFIP Conference, PO

asked us to present them our works

2013 January we got a benchmark from PO about dry composite forming

2013 April : first meeting with DUPONT about composite forming with resin …

2014 Paper presentation at Numisheet’14 conference (January 6th-9th

Mebourne Australia)

« Double dom composite forming simulation » V. DIVINE1 and E. BEAUCHESNE2 and al. …

2014 Ongoing benchmarks …

To be continued ….





Hyperform updates

Mapping


Draping

Conclusion

Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.

Two modeling approaches

Sandwich approach Independant layers approach

One part of shell elements

One material (law 25)

One multi-layers property

(type 10, 11, 17 or 19)

Fast, use to gives tendancies

No possible sliding between layers

No coupling between warp and weft

direction in case of woven fabric

N parts of shell elements

N material laws (law25 or law58)

N properties (type10, 11 or 16)

Contact between layers

Heavier but more accurate

Sliding between layers

Coupling between warp and weft

directions


Two modeling approaches

s11 s11 ~

s11 >> s11

~

Sandwich approach Independant layers

approach

No sliding between layers Sliding between layers


• Non-linear stiffsness behavior

• Softening, nominal stretch, bending factor

• Isotropic material

• Associated property (FABRIC) allows to

define the initial angle between warp and

weft.

Two materials

Material COMPSH (law 25) Material law FABRICA (law58)

nPP bWWF 1

PWFFF

FFFFF

2112

2

1244

2

222

2

1112211

2 sss

sssss

• Linear stiffsness behavior

• Plasticity domain available

• Pure orthotropic material

• Compatible properties (COMP,

SANDW, STACK, PLY) allow to define

only one fiber direction per layer

Coupling between fibers

warpweft


Sandwich approach for a 4 layers composite

UD

• 4 layers defined in the property

• Orientations : 0°, 45°, 90°, -45°

• Same thickness in each layer

• Material reference direction : X

• 2x4 layers defined in the property

• 4 layers for warp direction

• 4 layers for weft direction (coincidents

positions with warp’s layers )

Woven fabric


Independant layer approach for a 4 layers composite

UD

• Weft direction parameters >> Warp

direction parameters

• 4 independant parts of shell elements

• Contact interface in between

• Orientations : 0°, 45°, 90°, -45°

• Material reference direction : X

• Material FABRIC_A (law 58) :

Woven fabric

warpweft


Resin modeling for a sandwich approach

• Ogden Material (law 42) with basic shell property

r = 3/7*rresin = 1.09*10-09 Mg/mm³

Go = 0.50 MPa Gs= Go – Gl

Gl = 0.35 MPa β = Gs / η

Β = 5000 s η = 30 Pa*s

=> Soften heated resin parameters


Resin modeling for a sandwich approach

0°

45° 90°

/VISC/PRONY + CRASURV under validation ( 12.0.210 release )

Two parts with coincident nodes


Resin modeling for an independant layer approach

• Additional solids elements with coincidents nodes with upper and lower fiber

layers

+ =

Fiber layers Resin layers Fibers + resin composite

Shell element layers ( mat 58 /

prop 16 )

Solid elements layers ( mat

59 / prop 43 )


Resin modeling for an independant layer approach

• Material law « Connect » definition

• Elastic behavior then yield stress threshold in normal and tangential directions

• Plasticity domain defined from a yield stress and then by user functions,

• Strain rate dependancy available for user defined curves

• Contact interface is still maintain between layers of shell elements


Resin thinning during forming

Sandwich approach with a

coincident part for resin

Independant layers approach

with connected solid elements

for resin

Initial blank thickness = 1.5mm


Resin modeling and cooling

Cooling stage modeling

• Forming simulation is done without any thermal parameter

Resin material is set up to match with a cold resin

Stresses are then unbalanced between final stage of the

forming and initial stage of the spring back simulation





Hyperform updates

Mapping


Draping

Conclusion


B-Pillar model kinematic

The Die is going down

to the binder

The Die is going down

to the punch


Glass fibers (70%) Resin (30%)

• UD

E11 = 70%Eglass = 50400 MPa

E22 = 0.3 MPa

E33 = 50 MPa

r = 3/7*rresin = 1.09*10-09 Mg/mm³

Go = 0.50 MPa Gs= Go – Gl

Gl = 0.35 MPa β = Gs / η

Β = 5000 s η = 30 Pa*s

=> Soften heated resin parameters

Material description

• Woven fabric

E22 = E11

E33 = 50 Mpa

Initial shear angle 90°

4 layers : 0°, 45°, 90°, -45°


Sandwich approach for a 4 layers composite

UD


Sandwich approach : Blank end shape

High Shear

areas

Wrinkles Compression

UD


Sandwich approach : Fiber orientations

Fiber orientations are consistent with

blank shape

UD


Independant layer approach : 4 layers composite

UD


• Sliding effect between layers

Due to fiber orientations 0°, 45°, 90°, -45° regarding X axis, the behavior

during stamping is different for each layer

Independant layers approach : Blank end shape

UD


Independant layers approach : Blank end shape

• The same compression, tension and shear zone can be observed

• Wrinkles may also occur

High Shear areas

Wrinkles

Compression

UD


Independant layers approach : fiber rotations

UD


Independant layers approach : fiber rotations in layer 1

First direction

angle versus X

axis

Second direction

angle versus first

direction

Woven

Fabric


Time computation

• Computer configuration

SPMD 12 domains – 1 Thread per domain

Intel(R) Xeon(R) CPU E5649 @ 2.53GHz (x86_64), 2533 MHz, 64449 MB RAM, 62416 MB swap

Sandwich Number of cycles Elasped Time

UD 81986 1h57

Woven fabric 81986 2h35

Independant layers Number of cycles Elasped Time

UD or Woven fabric 81986 3h47

UD or Woven fabric + resin 81986 10h30

• Independant layers • 344423 nodes

• 345060 elements

• Sandwich • 103826 nodes

• 106260 elements

• Independant layers + connect • 344423 nodes

• 583860 elements

AMS x20





Hyperform updates

Mapping


Draping

Conclusion


HyperForm Radioss 13.0 updates for composite forming

• A composite option is available in User Process tree browser settings

• Type of modeling is then requested


Plies definiton

Layers are treated as

independant blanks

HyperForm Radioss 13.0 updates for composite forming

Sandwich approach Independant layers approach


Composite material

• Possibility to define an user material, and to save it into a database

• For the independant layer approach, new components need to be created

as for multi-layer blank configuration

• Then HF sets up automatically

• Contact interfaces tools and blank(s)

• Contact interface between layers

• Post-treatment cards in engine





Hyperform updates

Mapping


Draping

Conclusion


Mapping algorithm

Target integration points

Stamping integration points

Forming side Crash side

Mapping

??


NEW in HC 12.113

Second fiber direction mapping

Angle regarding the first

direction as iso-value

Fiber directions mapping


NEW in HC 12.113

4 layers of shell elements (MID 58, PID 16) on 1 layer of

shell elements (MAT25) associated with a 4 layer

sandwitch property (PROP11)

Target part

Composite

layers

Mapping for independant layers approach


Full stress tensor and 2 fiber directions mapping from 4x44826 shell elements (MID 58,

PID 16) on 6758 shell elements (4 layers sandwitch property)

Time : 6s (Intel Core 2.8 GHz / 16Go)

Layer 1

Layer 2

Mapping for a independant layers approach


Mapping of from a woven fabric modeling

• For a UD, the fiber direction is mapped on a target part associated with a

pure orthotropic material (law 25) => no issue

• For woven fabric, two fiber directions have to be on a target part

associated with a pure orthotropic material (law 25) => issue

The layers and the material associated to the target part will be duplicate.

The material parameters will be spread thru these new layers so that

NEW in HC 12.116

Reference

model Splitted layers

1 layer = 1 layer

1 layer

+


Mapping of from a woven fabric modeling

• Split method validation

Reference model Splitted layers





Hyperform updates

Mapping


Draping

Conclusion


Two modeling scales

No resin, only bi-directional composite fabric

Meso-scopic scale : modeling fibers with strip of shell elements

Macro-scopic : classical FE mesh and fabric Radioss material law

To provide customers with different levels of accuracy


4343

Meso-scopic scale approach

nPP bWWF 1

PWFFF

FFFFF

2112

2

1244

2

222

2

1112211

2 sss

sssss

Material : /MAT/LAW25 (COMPSH)

With E11 >> E22, E33

Property : /PROP/TYPE11 (SH_SANDW)

Angle < 50°

Angle ~90°


Dry composite with mesoscopic approach

• « Classical » crash model

• Imposed velocity : 0.1 m/s

• Impact on a rigid wall


Mapping from meso-scopic model to crash

Angle < 55°

Model to map and target mesh

Second direction after mapping : angle with the first direction

Target part after mapping and Re-zoning according to an angle of 55° criteria

E = 70%E, G = 70%G etc … ~ ~


Crash results comparison

Two models : free from forming results on the left side and with forming results and

rezoning on the right side


Comparison ref-global

=> Failure mode is not the same for the model with forming results

=> The model with forming results is stiffer than the one without.

Vertical failure mode

Horizontal failure mode


Comparison reference-meso-global

Models with forming results are stiffer than the one free from initial results.


Comparison reference-meso-global

=>Internal energy is higher when forming results are taken into account





Hyperform updates

Mapping


Draping

Conclusion

Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Copyright © 2012 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved. Copyright © 2014 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.

Drape Estimator for Composite Fibers

• Calculate

• Draping angles

• Thickness variation

• Interfaces

• OptiStruct

• Nastran

HM Drape Estimator (white) versus competition (red)


Drape Estimator for Composite Fibers

Material/Fiber direction defined on

the flat reference shape

Finale part geometry OneStep result : flat shape

Finale part initialised with

Material/fiber directions

OneStep

Fiber direction





Hyperform updates

Mapping


Draping

Conclusion


Several works and studies around composite forming with Radioss

Reduced input data, simple set up, reasonably fast and accurate

Different scales modeling approaches depending on the expected results

Influence of forming results on crash simulation results has been shown

Mapping with re-zoning allows to take into account material degradation

Mapping compatible with sandwitch (HC11.430) and multi-layers modeling (HC 12.113)

Validation is in progress …

Conclusion


THANK YOU !

Documents

ALTAIR Composites Forming Activities 2014