This document summarizes Altair's capabilities for simulating the forming of woven composite fibers and mapping the resulting fiber orientations to crash simulations. It describes: 1) Using HyperForm to simulate the double dome forming of a composite weave and map the resulting fiber shear angles to a crash model 2) Crash simulations showing the influence of the mapped fiber orientations on failure modes and structural response 3) Options for more advanced meso-scale forming simulations using shell or solid elements and SPH flow modeling

1. Innovation Intelligence®
Forming Simulation of Woven Composite
Fibers and its Influence on Crash
Performance
Dr Subir Roy
Senior Director, Industry Solutions
Altair

2. Copyright © 2013 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.
Outline
• Product Overview
• Study Objective
• Manufacturing processes
• Process simulation
• Mapping fiber orientation to crash model
• Crash simulation results
• Additional options

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Altair Manufacturing Solutions
Stamping Extrusion Casting
Injection
Molding Mapping
HyperForm
(HW)
HyperXtrude
(HW/Inspire)
Click2Cast
NovaCast
(APA)
Moldex
(APA)
HCRM (HW)
Converse (APA)
OptiStruct / HyperStudy

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HyperForm: Advanced Solution for Sheet Metal Forming
• Early feasibility analysis
• Material cost analysis
• Die face design
• Virtual try-out and process optimization
• Press hardening
• Die stress analysis and topology optimization
 Composite forming
 Initialization of structural CAE models

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Objective
1. Double Dome simulation of a composite weave [Ref. NUMISHEET’05]
2. Map fiber orientations from forming to crash model
3. Crash simulation to check influence of fiber orientations

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Composite Forming Process: RTM
Ref. CAMX 2014

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Composite Forming Process: Thermoforming
Ref. CAMX 2014

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Forming Simulation Model
• Blankholder force : 350N
• Initial blank size : 290mm * 190mm
• Tool speed : 170mm/sec
Blankholder
Punch
Die
Blank

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Weave Material Properties
• 1 layer of a Balanced Twill weave
• Stiffness behavior is non-linear in both warp and weft directions
• Shear stress is a function of shear angle

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Forming Simulation Results
• Shear angles at 13 points
 Consistent with shear stress distribution
Maximum shear angle = 36,9°

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Forming Simulation Results
• Stress and strain in warp direction
• Stress and strain in weft direction

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Crash Simulation Model
• Final fiber orientations are mapped on a coarser crash mesh using
HyperCrash Results Mapper (HCRM)
• Rupture criteria : Hashin failure
 Maximum stress value in direction 1 and 2, tension and compression
800mm/sec
Rigid wall

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Crash Simulation Results
• Normal resultant force against rigid wall shows a significant difference

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Summary
• Fabric material law in RADIOSS is able to model composite weave forming
 Physical behavior such as non-linearity of stiffness for warp and weft direction,
shear stress as a function of shear angle are modeled
• Final fiber orientations can be mapped to crash simulation model
 Fiber orientations resulting from stamping simulation influence rupture mode and
stiffness response for crash simulation

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Rapid Drape Estimator for Composite Fibers (13.0)
• Calculate
• Fiber orientation (draping) angles
• Thickness variation
• Interfaces
• OptiStruct
• Nastran
HM Drape Estimator (white) versus competition (red)

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Rapid Drape Estimator for LSDyna (14.0)

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• Model bands of woven fibers using shell elements
• Model individual woven fiber using solid elements
Advanced Meso-scale Modeling of Draping

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 SPH to model resin flow
Advanced Meso-scale Modeling with Resin
390 000 nodes
320 000 SPH cells
6 h on 24 CPUs
CPUs (Troy Cluster)

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• Macro-scale model
• Meso-scale patch at critical area
Coupling Macro and Meso-scale Modeling
Maximum shear angle region

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1. Forming simulation at macro-scale
2. Map the meso patch boundaries on the flat mesh
3. Extract the displacement history at boundaries
4. Simulate meso-scale model with displacement history
Indirect Coupling of Macro and Meso-scale Modeling

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Design Optimization Cycle
Forming:
(HyperForm)
Mapping
(HWRM )Performance
(OS/RADIOSS)
Design changes :
HyperMorph,
HyperStudy
Weave layup:
(CEDREM/HyperMesh)
OK?

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Thank you