Solver Enhancements and Research Directions

Dr. Franco Costa

June 2016

Autodesk® Moldflow® Insight

Senior Research Leader

© 2016 Autodesk

Validation

Moldflow 2017

Current Developments

Research Projects & Collaborations

Outline

Validation

© 2016 Autodesk

Highly Instrumented Box Tool with Conformal Channels

Validation: Transient Cool (FEM)

© 2016 Autodesk

PA 6 material molded 30wt% Glass Fiber

Cool (FEM) using Conduction solver

Agreement on temperature rise and timing

Validation: Transient Cool (FEM)

© 2016 Autodesk

Deflection along long edge

PA6 30wt%GF

Validation: Warp (3D)

© 2016 Autodesk

simhub.autodesk.com Validation Reports

Technical papers

What’s New

How to Videos

Where to Find Validation Reports

Moldflow 2017

© 2016 Autodesk

Consider all cavities and mold movement

Mold Cooling Analysis for 2K-Overmolding

© 2016 Autodesk

Consider all cavities and mold movement

Mold Cooling Analysis for 2K-Overmolding

© 2016 Autodesk

Mold Cooling Analysis for 2K-Overmolding

Cool (FEM), Transient results across multiple cycles

© 2016 Autodesk

Select “Transient from production start-up”

Mold Cooling Analysis for 2K-Overmolding

Set up one cycle

Results span two cycles

© 2016 Autodesk

Mold Cooling Analysis for 2K-Overmolding

Warpage analysis on final component only

© 2016 Autodesk

Cool (FEM) An initial Flow (Gas)

analysis is done to determine the gas core

Conduction or Flow on Every Iteration for part temperatures

3D Cool analysis for Gas Injection Molding

© 2016 Autodesk

Update the empirical relations for heat transfer coefficients from the cooling circuits at low/medium Reynolds numbers

Molding trials in the Instrumented Mold Unfilled PP

Coolant Heat Transfer for Low Reynolds Number

AMI 2017

AMI 2016

Measured Data

© 2016 Autodesk

Shaded plot by default

New Default Plot Type for Re-melt Zone Plot

© 2016 Autodesk

Allow user routines for selected properties and calculations User-coded routines in a DLL

Example Template provided

AMI 2016 : User viscosity routine

AMI 2017 : PVT & Core-shift

Future: Fiber Orientation ?

Curing ?

HTC ?

3D Flow “Solver API” Framework

© 2016 Autodesk

Motivation: Collaboration with Research Partners

Solver API

© 2016 Autodesk

Sample code included in Moldflow installation

Starting with the Solver API

© 2016 Autodesk

PVT 3D Warp

Core shift

More mesh and result utilities

Solver API: Extended

© 2016 Autodesk

SolverUserHb3dInitialize

SolverUserHb3dAnalysisSetup

SolverUserHb3dViscosity & SolverUserHb3dSpecificVolumeAtNode

SolverUserHb3dCoreShiftSolve

SolverUserHb3dTimeStepComplete

SolverUserHb3dCleanup

User DLL defined call-back functions

Initialize

Setup

Cleanup

Read Study File

Flow Calculation

Blank User Function

Viscosity & PVT

Temperature Calculation

Next Time Step

Next Iteration

Core Shift

© 2016 Autodesk

Implement via Solver API for PVT Allow other researchers to test

alternative PVT models

U. of Budapest have developed in-mold PVT measurement at high cooling rates Amorphous material

Presented at CONNECT!2014 Moldflow User Meeting

Cooling Rate effect on PVT

© 2016 Autodesk

Implement a cooling rate dependent PVT model in a user Solver API routine Shrinkage: Prediction vs Measured

Cooling Rate effect on PVT

© 2016 Autodesk

Output Cooling Rate at phase transition

Linear shrinkage prediction is lowered slightly

Cooling Rate effect on PVT: Solver API

© 2016 Autodesk

3D Flow Core-Back for Microcellular foaming

Chemical Blowing Agent Foaming

Allow overmolding of thermoset with thermoplastic & vice-versa

Improve accuracy of fiber orientation around the gate.

Increase the upper limit of initial fiber length and allow up to 100 mm long fibers in the simulation.

RSC model can be used for disk-like fillers (aspect ratio less than 1)

3D Warp Allow Mesh Aggregation when isolating causes of warp

Allow Anisotropic properties for part-inserts

Induction Heating for foaming processes (Microcellular and Chemical Blowing Agent)

DOE: Additional process variables and results

Other Improvements in Moldflow 2017

© 2016 Autodesk

• Cool for 2K-Overmolding

• Cool for Gas

• Core-back for Foaming

• Chemical Blowing Agent• Anisotropic Part Inserts

• New 3D Mesher

• Thermoset Inserts

• Fiber Model Controls

• Low Reynolds Number

• Enhanced Results & DOE

• Solver API extended

Moldflow Insight 2017

Current Developments

© 2016 Autodesk

Disclaimer

We may make statements regarding planned or future

development efforts for our existing or new products and

services. These statements are not intended to be a promise or

guarantee of future delivery of products, services or features but

merely reflect our current plans, which may change. Purchasing

decisions should not be made based upon reliance on these

statements.

The Company assumes no obligation to update these forward-

looking statements to reflect events that occur or circumstances

that exist or change after the date on which they were made.

© 2016 Autodesk

Improve 3D Fiber Orientation in Core Layer

Measured data provided by BASF

BASF PA 50%GF

• Investigating

• Orientation models

• Implementation

• Approximations

• Preliminary Results

© 2016 Autodesk

Preliminary Results

Higher concentration of fibers in the core region (through thickness)

Prediction of Fiber Migration

Measured data: G.M. Vélez-García, Compos. Part A-Appl. Vol 43: 104-113 (2012)

30wt% GF/PBT, 1.38mm thick, Center-Gated Disk

© 2016 Autodesk

Next Phases: Stress evolution

Detachment from mold (before ejection)

Consider viscoelastic stress relaxation

3D Residual Stress Shrinkage Model

Phase 1: Thermo-viscous-Elastic Model

Assume full mold constraintStandard AMI

Shrinkage Model

Warp Benchmark Case from Braun:

Measured Combined Deflection at

edges: 1.60mm

1.26mm

1.68mm

© 2016 Autodesk

0.00%

0.50%

1.00%

1.50%

2.00%

2.50%

3.00%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

In-plane Shrinkages

Experimental Current Model 3D Residual Stress Model

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Cha

ng

e in

Corn

er A

ng

le

Corner Angle Change

Experiments Current Model 3D Residual Stress Model

3D thermo-viscous-elastic model

In-cavity residual stresses are calculated until room temperature

Takes advantage of material shrinkage measurement data if available

3D Residual Stress Shrinkage Model

© 2016 Autodesk

Thermocouple-controlled Cooling (Pulse CoolingTM)

© 2016 Autodesk

Improving accuracy of weld-strength models for future use in Helius-AME

Weld Surface Strength -3D

© 2016 Autodesk

Mat Orientation

Resin Transfer Molding 3D

Non-Newtonian, non-isothermal flow

(Melt: 30C, Mold:150C)

Anisotropic permeability

Include Vacuum pressure & Gravity

ResultsDegree of Cure, Volumetric shrinkage,

Part Thickness, Permeability, etc.Pressure During Filling

© 2016 Autodesk

• “Free slip”, or slip without friction, is equivalent to the capability offered in TP -2016

• “With friction”: a slip velocity model, with slip velocity being a function of shear stress, is applied

Wall Slip (3D) – Slip Friction Coefficient

© 2016 Autodesk

Accurate 3D flow simulation Flow pattern

Velocity & pressure field

Temperature field

Inertia effect

Wall-slip effect

Metal Injection Molding

Accurate Material propertiesMaterial testing

Data fitting

Powder concentration predictionDetect black line defect

Fill time Powder concentration

Low concentration regions, possible black

line defects

© 2016 Autodesk

Using embedded Nastran FEA solution

Useful to check for balanced ejection and avoid visible stress marks

Ejection Analysis: Force from Ejectors

© 2016 Autodesk

Enhancement on Robustness Enhancement of detecting contact surface between plastic

product and mold core

Enhancement on Accuracy Residual Stress from flow -> initial strain for Nastran

Automatic Detecting based

on ejectors movement direction

User check, add or remove surface

elements manually

Final contact surface

Von Mises Stress During Ejection

Ejection Force

© 2016 Autodesk

Previously, mold blocks are represented by regions.

If inserts are present, users need to stitch contact interfaces to form mold internal boundary

Create CAD Bodies for Mold Block Creation & Meshing

CAD body for mold block

Contact

Face

Now we can create CAD bodies for mold blocks.

Users do NOT need to stitch contact interfaces manually

Surface mesh for mold block

© 2016 Autodesk

Apply appropriate edge length and chord angle on faces automatically

Large bodies have larger edge lengths

Similar edge lengths on contact interfaces

Chord angle applied on faces with high curvature except for fillets

No big increases in element counts

Users do not need to deal with small faces individually

Surface meshes will be more smooth than previous versions

Auto Sizing for CAD

© 2016 Autodesk

• Fiber Orientation

• Fiber and particle migration

• 3D Residual Stress

• PulseTM Cooling• Weld-line Surface Strength

• 3D RTM / Infusion

• Wall Slip with Friction

• Metal Injection Molding

• Ejection Force

• Easier Mold Meshing• Auto sizing for CAD meshing

Current Developments

Research

© 2016 Autodesk

Improve on the bubble nucleation modeling, dependent on pressure history, and local stresses around fillers (talc, fiber)

Vahid Shaayegan presented at AU2015

Microcellular Bubble Nucleation– University of Toronto

© 2016 Autodesk

Thermoplastic Injection OverMolding of composites

Interface Aniform draping solution to Moldflow Warp analysis of the combined structure

Model bond strength

Injection Overmolding of Continuous Fibers Composites - TPRC

© 2016 Autodesk

Model non-recoverable deformation and resistance of a continuous fiber composite being compression overmolded

Composite Overmolding – Huazhong University

© 2016 Autodesk

Prediction of long fiber breakage during melting in injection barrel

Aim: Initial fiber length distribution for polymer at the sprue tip

Fiber Breakage in Barrel– University of Bradford

© 2016 Autodesk

Prediction of fiber orientation and breakage during injection molding of “long” carbon fiber thermoplastics

2mm to 12mm

Long Carbon Fiber Injection Molded:PNNL, Toyota, UIUC, Plasticomp, Magna, Virginia Tech

© 2016 Autodesk

50%wt LCF/PP (slow-fill)

Long Carbon Fiber Project – Phase 1

C C

30wt%LCF/PP slow fill

Location C

Fiber Orientation Fiber Length

© 2016 Autodesk

Molding on ribbed structural part

Long Carbon Fiber Thermoplastic: Phase 2

© 2016 Autodesk

US DOE funding to develop ICME for carbon fiber draped and compression molded parts (Automotive)

Autodesk invited to provide process modeling of

Compression molding

Fiber Orientation

Local fiber volume fraction

Chopped Carbon Fiber Compression

© 2016 Autodesk

Model the viscosity reduction which occurs due to high shear and leads to advanced flow at part edges

Aim: Improve fill pattern & air-trap prediction

Racetrack / Flow Imbalance– Budapest University (BUTE)

© 2016 Autodesk

Mold to observe flow imbalances after different flow lengths

Racetrack / Flow Imbalance– Budapest University (BUTE)

© 2016 Autodesk

Model the change in viscosity due to filler migration, fiber orientation and fiber breakage

Improve: Fiber orientation

Pressure prediction

Add Filler Volume Fraction effect

Filler effect on Viscosity - RMIT

© 2016 Autodesk

Calculate the mold life and approximated range of cycles

Will use Autodesk Nastran fatigue solver

Support rapid heating cycle molding

Consider 3 major causes of mold damage

Mold Fatigue - Seeking Industrial Collaborators

Fatigue Module

Clamping-force-

induced Stress

Thermal Stress

Pressure-induced

Stress

© 2016 Autodesk

Flow instability

Looking for collaboration / case-studies (aimed at Automotive parts)

Surface Appearance (Tiger Stripes)

© 2016 Autodesk

Microcellular Foaming

Composite Overmolding

Long Fiber Breakage & Orientation

Long Carbon Fiber Injection Molding & Compression Molding (SMC)

Flow advancement at part edges

Viscosity Effects / Fiber

Mold Fatigue

Tiger Stripes

Summary of Long Term Research Collaborations

© 2016 Autodesk

Some New API Scripts….

MapOvermold including Fiber Orientation

3D Surface Shrink

3-2-1 Warp Deflection

© 2016 Autodesk. All Rights Reserved.