topologioptimering i industrin¶nköping 2010-10-07/ma… · 1993 linear statics. normal modes....

Copyright © 2009 Altair Engineering, Inc. Proprietary and Confidential. All rights reserved.

Magnus HermodssonAltair Engineering

Topologioptimering i industrinProOpt Jönköping 20101007


Altair HyperWorks: A Platform for Innovation


Different disciplines covering the entire development process

Topology (Optistruct)

Topography (Optistruct)

Size and Shape (Optistruct/HyperStudy)

DOE and Stochastic (HyperStudy)

Optimization in the Design Process


Altair Solver and Optimization Roadmap

1993 Linear StaticsNormal Modes

2006 AMLS

2002 MotionSolve

2000 Buckling

1993 Topology

2002 Freq Response

2003 Contact

2000 Draw Direction Constraint

1999 Topography

2001 Size & Shape

2005 MBD in OS

Transient & Thermal

2005 Free Size, ShapeSix Sigma

Pro

duct

ivity 2004 Cross Section

Constraint

Impact on Product Design

20 years experience!


FEA-based Structural Optimization

Conv ?

Sensitivity Analysis

Solve ApproximateProblem

Search ApproximateProblem

Optimum

FE Analysis

Conv ?

Calculate mass, stiffness, strength, stability

Calculate derivatives of mass, stiffness, strength, stability depending on variables Adjoint (topo) vs direct

Approximate and solve optimization problem (how to change variables to e.g. minimize mass and meet requirements)


What is the best material distribution in the design space in search for the stiffest design for a given load?

Topology Optimization


Material inside the design space is assumed to be non-homogeneous with a relative density between 0 and 1

Elasticity properties are a function of density

Density = 1

Density = 0



Finite element discretization of the design space

Function between density and elasticity using penalty factor p

Density = 1

Density = 0

Topology OptimizationDensity Method

E/E0

ρ/ρ0

(ρ/ρ0)p

1

1


Problem solution using finite elements and iterative optimization procedure

Density = 1

Density = 0


E/E0

ρ/ρ0

(ρ/ρ0)p

1

1

Optimization Problem:

• Minimize Objective

• Obey Constraints


Manufacturing Constrains – Topology

• Min/Max Member Size

• Draw Direction

• Extrusion

• Symmetry

• Pattern Repetition

• Cyclic Repetition

No symmetry XZ, YZ symmetry

YZ symmetry XZ symmetry


Common Topology Optimization Problems

Minimize (weighted / total / regional) compliance

with constrained (total / regional) volume / mass fraction

Minimize (total / regional) volume/ mass fraction

with constrained displacements

Maximize (weighted) frequency


Minimize (total / regional) volume / mass fraction

with constrained frequencies

Minimize combined compliance and frequencies


Minimize (total / regional) volume/ mass fraction

with stress constraints


Topology Optimization with stress Constraints

• Global von mises stress constraints

• Apply to entire model including non design space

• Stress constraints for a partial domain of the structure are not allowed

• The reason is that it often creates an ill-posed optimization problem as elimination of the partial domain would remove all stress constraints

• Local stresses are still high

• This is for general stress level control

• Local stress should be taken care of by using shape/size

Stress < 50 Stress < 30


Drivkrafter och motivation

Användarperspektivet

• Relativt ny teknologi – spännande!

• Tilltalande resultat – wow!



Produktutvecklingsperspektivet

• Viktsbesparing – Automotive, Aero

• Materialkostnad – masstillverkning, gjutkomponenter

• Prestanda – motordetaljer, mekanismer

• Förbättring av befintlig produkt

• Reducerad utvecklingskostnad


Radiator Mounting Bracket Design

Initial Design Package Space

Optimized Design

OptiStruct proposal and final design

Stress Displacement Mass Original Design


Old Frame

New Frame

Mass reduction: 20%Increase torsion stiffness: 31%Weld length reduction: 50%

SUV Frame Design



Prestanda - mekanismer



Förbättring av befintlig produkt - PowerTrain



Exempel: min(komplians)

Förbättring av befintlig produkt - PowerTrain


Concept Design

Detailed Product Design Manufacturing

Product Development Cycle

CAEToda

y

Concept Design and Optimization

Detailed Product Design Manufacturing

CAE

Idea

lStructural optimization moves CAE Upstream

CAE upstream tomitigate the classical

design paradox

Concept

Design freedom

Design knowledge

Preliminary Detailed

Time



Invändningar

• ”Vi hinner inte sätta oss in i detta”• Programmen blir mer och mer lättanvända och integrerade i befintlig CAE-

miljö. Mycket av fokus ligger på användarvänlighet (nyheter i HW v11)

• ”Vi litar inte på resultaten”

• Resultat från topologioptimering bör alltid bedömas utifrån ingenjörsmässiga grunder.

• Verifierande beräkning bör alltid göras på nya koncept.

• Robusthet?

• Utför verifierande känslighetsanalys map laster och dimensioner


‘In the Works’

• New Features• Multiple Start Point Optimization• Non-Linear Optimization (NLGEOM)

• Usability and Functionality• Topology Optimization for MBD using ESL• New Shape Optimization Algorithm• Manufacturing Constraints for Topology Optimization• Composite Optimization Enhancements• External Response Handling• NVH Optimization Improvements• DVPREL for ZOFFS• OSSmooth Enhancements

• Performance• Speed Up for Large Scale Optimization Problems


Dynamic Loads – Equivalent Static Load Method

• Flexible dealing with dynamic problems considering true time history and not just worst case time step

AnalysisDynamic Problem

Load time history

OptimizationStatic Problem

Equivalent static loads

Load

Design variables

fteq = Kdt

t

d


Topology Optimization for MBD using ESL


No – Hole Casting


Stamping Constraint


OSSmooth Enhancements

• Implementation for multiple design components; preserving the component boundaries for the recovered mesh.

• Redesign of the OSSmooth panel: adding subpanels, for geometry recovery for reanalysis, and one with existing OSSmooth options.

• Provide user the option to have geometry recovery without the artificial layer of elements.

• Work on improving the quality of the recovered mesh.


• Keep narrow layer

• Split non-design space

• Tetra Mesh Iso-surface ‘by property’

• Preserve Boundary Conditions

OSSmooth Enhancements


Thermal Optimization

Temperature as objective function or constraints (DRESP1)• Response from other solution sequence such as volume, mass, displacement,

etc.

Shape and Sizing optimization• Topology under development


Versailles 27-29 October

topologioptimering i industrin¶nköping 2010-10-07/ma… · 1993 linear statics. normal modes....

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