Automated model creation in

Abaqus/CAE

R Habermann, Darmstadt, 21.11.2019

2 © NSK Europe – Confidential

Motivation for automatic methods

2 h 2 h

1980-2010

Small project

Model creation

FEM calculation

Complex project

1 week 1 week

2 h 5 min

Since 2010

Small project Complex project

1 week

2 h

3 © NSK Europe – Confidential

FEM Calculation (Example)

Spec:

Forces, BCs, Interactions, Machine elements,

Type of analysis,…

24 Subassemblies

69 Parts

Assembly FEM

Fiscal Requirement

Time (Man-days FEM Specialist,

time to report)

4 © NSK Europe – Confidential

Manual model creation in Abaqus/CAE

1 Assembly

65 Parts

Import in Abaqus

Abstraction, Interactions,

Meshing, Connectors…

Time for model creation by specialist: 1 Week

1 Assembly

26 Parts

38 Interactions

5 © NSK Europe – Confidential

Existing Strategies to speed up model creation

Templates

FEM Apps

3Dexperience

Source: COMSOL: COMSOL Multiphysics® 5.1 Release Highlights,

https://www.comsol.de/release/5.1/application-builde

Source: Sharma, B., Kulkarni, M., Sundararaja, S.:

Automation of CAE Tasks to Improve Work Efficiency,

http://www.altairatc.com/india/2017/2017-technical-

papers/Mod&Viz/01_Mod_IATC2017_Paper_Maruti.pdf

Source: Dassault Systems User Assistance R2019x: Simulation > Simulation Process

Modeling > Performance Study > Input and Output Parameters > Editing the

Parameters of a Simulation Process

6 © NSK Europe – Confidential

Criticism on the State of art

Manual Creation: Too much time needed

Templates: Good idea, but creation of the template itself is still time consuming, programming

knowledge needed

FEM Apps: Really fast execution times, but even more focused on one particular simulation case

Wanted: Method to speed up the first model creation significantly, without programming

knowledge. Useable with a GUI or text based. Additional design iterations should be

nearly instantaneous

7 © NSK Europe – Confidential

AutoFEM

› Names

› Materials

› Loads

› …

CAD model preparation

Framework & GUI

/CAE

8 © NSK Europe – Confidential

Catia Model preparation

24 Assemblies

69 Parts

Export assembly as

CATpart

Designer:

Hide unimportant parts and abstract parts

Create surfaces, lines and points

Create poses

1 Assembly

16 Parts

Time for model abstraction:

4 hours

Surface Point

Line

9 © NSK Europe – Confidential

First AutoFEM run

16 Parts Surface Points

Line

1 Assembly

16 Parts

Surface Point

Line

Automatic creation of surfaces in parts,

datum lines and points, with useful

named sets, parts and so on

10 © NSK Europe – Confidential

Model creation with the AutoFEM

Manual model creation directly in the cnp file or in the GUI

11 © NSK Europe – Confidential

Highlights of the AutoFEM

Orphan meshes with automatic mesh association

Rotational symmetry for automatic hexahedral meshing

Metaprogramming (use of variables, generators and arguments)

Easy switch between standard and explicit

No dependency of topological changes or mesh quality

Included complex bearing modelling

Rigid parts supported

Complete model creation with output of finished input file

Documentation in DocuWiki

GUI in active development

12 © NSK Europe – Confidential

Orphan mesh

CAD Part with Logo Orphan mesh

Automatically merged

Automatic mesh association, based

on cad faces

13 © NSK Europe – Confidential

Rotational symmetry

Original CAD Part

Cross section

Rotational symmetric part

14 © NSK Europe – Confidential

Metaprogramming

Use of a variables and arguments, some mathematical expressions are allowed, but only in [Variable].

[Variable]

SpacerHSIS = !arg1 + 0.855

GearForceX = 57936

GearForceY = 89945

GearForceZ = 204741

GearForce = %GearForceX, -1*%GearForceY, -1*%GearForceZ

Spacer1 = int(!arg1 * -1000)

The variables can be accessed anywhere in the config file by using the % sign, e.g.

[Load_2]

Type = Line

Name = Gear

Feature = Gear

Value = %GearForce

StepOn = Load

15 © NSK Europe – Confidential

Complex bearing modelling

5 nonlinear connectors

per roller element

RBE 3

Connector align

with nodes

16 © NSK Europe – Confidential

No dependency of topological changes or mesh quality

For small parametric changes, the associative interface is a very good and cost effective solution for an

iterative design process.

For one shot assemblies or iterative design processes with big topological changes, the AutoFEM is faster

and more robust.

CAD P

1

P2

50 mm

20 m

m

FEM

50 mm

20 m

m

FEM

Extra features

Associative Interface AutoFEM

CAD

P1

P2

50 mm

20 m

m

FEM

50 mm

20 m

m

FEM

Extra features

17 © NSK Europe – Confidential

Documentation

Complete, up to date documentation of the API

Examples in preparation

GUI in development

18 © NSK Europe – Confidential

Complete model creation with output of finished input file

Up to date:

Complex static wind models with nonlinear bearings, parametric spacer setting

Model creation from 6 months down to 2 weeks

Explicit orbital cold deformation with ALE (Swaging)

Modal analysis of steering systems

Clamping of complex mechanical systems (over 70 interactions)

Very fast iterative design cycles for Hub and Powertrain components