coretech system co., ltd. │ copyright© 2021 moldex3d. all

CoreTech System Co., Ltd. │ Copyright© 2021 Moldex3D. All rights reserved.

Biuro konstrukcyjne PawForm

Micromechanics Interface

CoreTech System Co., Ltd. │ Copyright© 2021 Moldex3D. All rights reserved.No contents are construed as providing a warranty, including any warranty of merchantability, accuracy, completeness, or fitness for purpose, or representation for which CoreTech System Co., Ltd. assumes any legal responsibility.

Contents

Introduction

Concepts of Micromechanics Interface analysis

Micromechanics Interface Features and Benefits

Case Investigation

Foam Injection Molding results interpretation

Structure validation

Conclusion


Introduction


Why Micromechanics Interface

More considerations for nonlinear multi-scale material modeling simulation with integration of Digimat or Converse into FEA software

Provide more efficient and accurate structural analysis of composite materials

Give users an opportunity to solve complex nonlinear multi-scale finite element problems

Micromechanics Interface

Composite material

analysis

FEA software

Nonlinear analysis


What Micromechanics Interface can Simulate

Some unique material properties can be considered into the multi-scale model

￭ Anisotropic, corresponding to the microstructure morphology

￭ Heterogeneous, corresponding to the microstructure morphology

￭ Nonlinear, elasto-plastic

￭ Fatigue

￭ Failure

￭ Strain-Rate dependent, visco-elastic


Micromechanics Analysis Procedure

Moldex3D E.g. ANSYS / ABAQUS / LS-DYNA

Foaming

*Foam Injection Molding supports Digimat only

LS-DYNA


Features and Benefits


Direct Interface for Analysis

Interfacing with the output items for Digimat and Converse analysis before FEA software


Supported Output Files Function Items

DescriptionFile

name

Weld line

Weld line definitions are imported in Digimat-MAP in the form of node sets. This allow to export these sets to CAE codes, using proper element set definition, in order to assign them particular material properties.

*.nwd

Fiber orientation

Export the fiber orientation data for further analysis to view characteristics of fiber.

*.o2d

Flow-inducedresidual stress

When the mold opens to extract the part, those residual stress induce part deformations. Digimat-MAP is there to map such data input and allow to account for it as inputs of mechanical simulations.

*.s2d

Temperature

Temperatures before this cooling step could then be exported from the injection simulation results to Digimat-MAP. Digimat-MAP allows to map those temperatures from the injection mesh onto the structural mesh in order to perform a warpage analysis in CAE simulation software.

*.t2d

Foaming

Export the cell size and cell density data for

analysis to observe the mechanical properties

of foaming structure. Digimat-MF and

Digimat-CAE can transform the element modulus.

*.m2d

Note: Converse supports *.o2d (Fiber orientation output) ONLY


Options of Digimat Output

Support Digimat output for ANSYS, ABAQUS, MSC-Nastran, Marc, LS-DYNA and Optistruct

To cover complete process-induced variation during the molding processes, the output items include:

￭ Fiber orientation

￭ Weld line region data

￭ Residual stress

• Digimat-MAP allows to map the residual stress data and account it as input of mechanical simulations

￭ Temperature distribution at EOP and EOC

• Include part and part insert object

• Temperature before and after the cooling step could be used to perform warpage analysis by Digimat

Benefit

Users can determine more molding process-induced results and apply it into micromechanics consideration


Option of Digimat Output for Foam Injection Molding Analysis

A new workflow for foam injection molding part structural performance evaluation

Moldex3D can output cell size and cell density to Digimat

Benefit

Completely consider the cell size and cell density in foam injection molding parts


Case Investigation 1 Foam Injection Molding Results Interpretation


Challenges

In this case, four particular areas are identified to further study the effects of Foam Injection Molding:

￭ (1) Sink marks

￭ (2) Warpage

￭ (3) Cell size prediction and validation

￭ (4) Cell density prediction and validation


Specific Features

Specific features are added to the part design to further help evaluate, measure, and compare results

Different surface properties(mirror polishing, textures)

Ribs

Max rib-wall ratio 2:1

References for measurements

U-shape to amplify the deformations

Holes to generate weld lines


Cell Size Prediction and Validation

SEM validation:

average cell size 77 µm

SEM validation:

average cell size 58 µm

At the end of flow area, the material has travelled the

entire path which allows the cell to grow; also, the

pressure at the flow front is low and makes no

constraints on the growth of bubbles.

It is observed in both simulation and SEM validation

that the large cells are formed. Also, the cell sizes may

vary in different parts of this region.


Cell Density Prediction and Validation

SEM

SEM

At the end of flow area, the bubbles are developed

and merged together, resulting in very low density

with only a few cells visualized by SEM


Mesh Mapping

Mapping software

￭ Transferring data between two dissimilar meshes

Reduce the number of nodes and elements with mapping


Data Mapping

Users can map the density, size, volume of porosity from Moldex3D onto Marc

Density of porosity Size of porosity Volume Fraction of porosity


Physical Test Case 1

Accurately predict mechanical behaviour

The force-displacement curve of simulation is very close to that of experiment


Summary

Moldex3D Foam Injection Molding is not only able to calculate the nucleation and growth of microcellular bubbles, microcellular bubble size, number, density distribution, volumetric shrinkage, but predict the effects of bubble structure onpart warpage

Through Micromechanics Interface, the density, size, volume of cell are all considered into the structural analysis to make the results closer to the reality


Case Investigation 2 Structure Validation


Model Information

PP with 30% GF


Weld Line Prediction

Two gates lead to the generation of weld line in the middle area

Weld line


Fiber Orientation Prediction

The fiber orientation is highly aligned along the Y-direction in the middle area


Export the Data from Moldex3D to LS-DYNA

Direct selections of output item from Moldex3D to FEA software

Export fiber orientation and weld line

results from Moldex3D


Data Mapping

Map the fiber orientation and weld line onto LS-DYNA

element:407,612

mat:12,863

curve:347,301

Weld line


Boundary settings in LS-DYNA

A ball dropped at a height of 30 cm with an initial velocity

Velocity

fixed

fixed

fixed


Fracture Behaviour

Isotropic and homogeneous Isotropic and NonhomogeneousAnisotropic and

Nonhomogeneous

Cracked length for PP with weld line is longer than that for PP without weld line

Crack length for anisotropic case is just 20% of that for isotropic case

PP without fiber PP without fiber PP with 30% GF

Weld line


Summary

Provide precise predictions of fiber distribution and orientation

Take fiber orientation and weld line into account for fiber-reinforced composite materials to have efficient fracture behaviour validation and enhance the strength of product structure successfully


Conclusion


Moldex3D Micromechanics Interface

Give a plus for integration of Digimat or Converse to bring users an enhanced prediction accuracy of structural behaviourfor linear, nonlinear and anisotropic thermo-mechanical properties of a multi-phase material based on the material microstructure morphology, such as fiber and cell

Help users simulate complex nonlinear multi-scale finite element problems with composite materials, and have more accurate structural performance

coretech system co., ltd. │ copyright© 2021 moldex3d. all

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