Simulation With Nonlinear Structural Materials Asme Webinar

8/18/2019 Simulation With Nonlinear Structural Materials Asme Webinar

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Agenda

• Multiphysics Modeling

• Structural Modeling

– Nonlinear Materials

– Sources of Nonlinearity

– Modeling options

• Video demo

• Q&A

•

How To – Try COMSOL Multiphysics

– Contact Us


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Why Do We Model?

• Conception and understanding

• Design and optimization

• Testing and verification

Conjugate heat transfer simulation of

an aluminum heat sink.


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Modeling with COMSOL Multiphysics®

• Electrical, Mechanical, Fluid, and Chemical Simulations

• Multiphysics – Coupled phenomena

– Two or more physics phenomena that affect each other with no

limitation on which combinations or how many combinations

• Single physics

– One integrated environment – different physics and applications

– One day you work on Heat Transfer, next day Structural Analysis, then

Fluid Flow, etc.

– Same workflow for any type of modeling

• Enables cross-disciplinary product development and a unified

simulation platform


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Microwave Three-port Circulator

Porous Reactor

Radiation Pattern of a

Broadband Conical Antenna Fluid-Structure Interaction of a

Solar Panel

Acoustics Speaker Systems

Enables Technology Design Innovations


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Optimized Green Technology Design

• Solar panels are subject to wind loads

• Must be engineered to bend with the flow

• Physics involved

–

Fluid-Structural Interaction (FSI)• Fluid Flow

• Structural Displacement


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All Inclusive Interactive Modeling Environment

Model Builder

Provides instant

access to any part of

the model settings

• CAD/Geometry• Materials

• Physics

• Mesh

• Solve

• Results

Graphics

Ultrafast graphic presentation, stunning

visualization, and multiple plots

COMSOL Desktop™ Straightforward to

use, it gives full

insight and control

over the modeling

process


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Product Suite


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Constitutive Modeling

• Structural

– Linear elastic

– Linear viscoelastic

• Nonlinear

– Creep – Hyperelastic

– Elastoplastic

– Viscoplastic

• Geomechanics

– Concrete

– Rock

– Solid plasticity

s

e

s

e


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Nonlinear: Creep Models

• Norton

• Norton-Bailey

• Garofalo

• Nabarro-Herring• Coble

• Weertman

• Potential

• Volumetric

• Deviatoric

• User defined

Stress response of a

combined Norton and

Norton-Bailey material


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Nonlinear: Hyperelastic Models

• Neo-Hookean

• St Venant-Kirchhoff

• Money-Rivlin

– Two, five and nine parameters

• Yeoh

• Ogden

• Varga

• Arruda-Boyce

• Blatz-Ko

• Murnaghan

• User defined

Rubber velocity joint, model

courtesy of Metelli S.p.A.,

Italy


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Nonlinear: Elastoplastic Models

• Large strain plasticity

• Yield criteria

– Tresca

– von Mises

–

Hill plasticity• Hardening

– Isotropic

– Orthotropic

– Kinematic

•Plastic flow – Associated

– Non-associated

• User defined

Stress distribution

in a stent at balloon

inflation


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Nonlinear: Viscoplastic Model

• Anand

Viscoplastic creep in solder joints

under thermal loading


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• Bresler-Pister

• Willam-Warnke

• Ottosen

•

Material option – Tension cut-off

• Hoek-Brown

• Generalized Hoek-Brown

Geomechanics: Concrete and Rock Models

Stress distribution in

a concrete beam


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Geomechanics: Soil Plasticity Models

• Mohr-Coulomb

• Drucker-Prager

• Lade-Duncan

•

Matsuoka-Nakai• Cam-Clay

• User defined

• Material options

– Compressive cap

– Tension cut-off Stress distribution aroundan excavated tunnel


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Model Builder and Settings


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Study and Element Types

• Study types

– Stationary

– Transient

» Direct and modal

• Eigenfrequency

– Prestressed

• Frequency response

– Direct and modal

– Prestressed

• Linear Buckling

• Parametric

• Element types

– Solid

– Shell

– Membrane

–

Plate – Beam

– Truss


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CAD & Meshing Interoperability

3D CAD File Formats

ACIS®

Catia® V5

Creo™ Parametric

IGES

Inventor®Parasolid®

Pro/ENGINEER®

SolidWorks®

STEP

Meshing Products

Mimics®

+FE Module (Simpleware®)

Avizo®2D CAD File Formats

DXF

E-CAD File Formats

GDS/NETEX-G

ODB++

Mesh File Formats

NASTRAN

STL

VRML


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Multiphysics: Thermal Stress

• Multiphysics interface

• Coupled structural and

thermal analysis

• Mechanical boundaries

– Loads

– Constraints

• Thermal boundaries

– Conduction

– Heat flow

– Heat generation

– Radiation

Bipolar plate in a fuel cell: Thermal stresses in aconstrained plate


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Multiphysics: Joule Heating and Thermal

Expansion


• Physics coupling

– electric current conduction

– heat conduction

– heat generation

– structural stresses and strains

due to thermal expansion

Thermal actuator:

Temperature gradient


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Multiphysics: Piezoelectric Devices


• Constitutive modeling

– Piezoelectric

– Purely solid

– Purely dielectric

• Initial electric displacement

• Electrostatic boundary

• Piezoelectric dampingSandwich beam with piezoelectric ceramic actuator:Bending deflection due to shear stress


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Geometric Nonlinearity

• The response of the majority of the structures can be

analysed under the assumption of small displacement theory

• In some situations the change in the configuration cannot be

ignored – it is necessary to calculate the equilibrium with respect to the

deformed configuration

• The classical strain measures (engineering strains) are no

longer able to describe large displacements and/or largerotations

– new strain measures must be considered (Green-Lagrange strains)


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Strain Evaluation Options

• Small plastic strains

– Additive decomposition of

strains

• Large plastic strains

– Multiplicative decomposition

of deformation gradient.

Necking of an

elastoplastic metal bar

large

small


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Modeling Options

• Enable plasticity in sub-

domain

• Combine different material

nonlinearities

– Plasticity-creep

– Creep-creep

• Geometry directed material

orientation

Plasticity in an orthotropic container


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Creep and Viscoplasticity Options

• Often refer to as rate-

dependent plasticity

• Creep strains are added as

inelastic strains

• Combine predefined

materials

• Predefined temperature

dependency

• User defined creep

properties


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Soil Plasticity Options

• Elliptic cap

• Tension cut-off

• Dilatation angle in plastic

potential

• Parameter match to Mohr-

Coulomb


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Hyperelastic Energy Evaluation

• Nearly incompressible

materials

– Pressure (mixed formulation)

– Prevent locking

• Userdefined energy

functions


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User Defined Inelastic Strains

• Materials which exhibit a nonlinear stress-strain relation, even

at infinitesimal strains

– Brittle materials (ceramics, metal alloys)

– Ramberg-Osgood

– Damage function

• You can add distributed ODEs or PDEs to account for inelastic

strains

• Add inelastic strains with the Initial Stress and Strain node


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Parameterized Material Models

Temperature dependent plasticity in a pressure vessel


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Model Library


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Video Demo: Pressurized Orthotropic Container

• A container made of rolled steel is subjected to an internal

overpressure where one of the three material principal

directions has a higher yield stress than the other two

– Hill’s orthotropic plasticity is used to model the differences in yield

strength


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Q&A Session

Any questions not answered during the broadcast

will be answered via email.


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Product Suite


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Try COMSOL Multiphysics

• North America

– Pasadena, CA

– Downers Grove, IL

– Sugar Land, TX

– Tempe, AZ

– Danbury, CT

– Washington, DC

– Waltham, MA

– Irvine, CA

– Las Vegas, NV

– Atlanta, GA

• Europe – Dresden, Germany – Madrid, Spain – Grenoble, France – Yverdon, Switzerland – Jena, Germany – Antwerpen, Belgium – Narvik, Norway – Berlin, Germany – Roma, Italy – Salerno, Italy

• Register to our free hands-onworkshops at

www.comsol.com/events

http://www.comsol.com/eventshttp://www.comsol.com/events


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Contact Us

• www.comsol.com

– User Stories

– Videos

– Model Gallery

– Discussion Forum

– Blog

– Product News

• [email protected]

– General inquiries

• [email protected]

– Technical support
http://www.comsol.com/mailto:[email protected]:[email protected]:[email protected]:[email protected]://www.comsol.com/

Documents

Simulation With Nonlinear Structural Materials Asme Webinar