Topology Optimization in ANSYS - Midwest ANSYS User Group

27 Pages·2005·0.55 MB·English

Topology Optimization in ANSYS
Presented by:
Brian King
Analysis Project Engineer
IMPACT Engineering Solutions, Inc.
Tel: [phone]
E-mail: [email protected]
www.impactengsol.com
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About IMPACT…
Founded in 1987, IMPACT Engineering Solutions Inc. has grown
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into a market leader, providing technology based engineering
services
Focused on solid modeling since 1993
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Key IMPACT Product Offerings:
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Design Support
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Staff Augmentation
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Product Simulation
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Professional Services
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Analysis Services Division Initiated October 2002
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Gurnee, IL Office Opened in November 2003
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Analysis Capabilities and Expertise
COSMOSWorks Structure/Motion
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Pro/MECHANICA Structure/Motion
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MSC.NASTRAN / NE/Nastran
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FEMAP Pre & Post-Processing
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ANSYS
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CFDesign – CFD Simulation
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LS-DYNA – Drop and Crash Testing
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FE-Fatigue (nCode) Durability Analysis
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Extensive combined engineering analysis experience in a variety of
materials and industries
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©2005 –IMPACT Engineering Solutions, Inc.
What is Topological Optimization?
Layout optimization
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Try to find the best use of material for a body
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No optimization parameters need to be defined
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The material distribution function over a body is the
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optimization parameter
The goal (objective function) is to minimize /
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maximize the energy of structural compliance or
maximize the natural frequency while satisfying the
constraints specified
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©2005 –IMPACT Engineering Solutions, Inc.
What is Topological Optimization?
The design variables are pseudo-densities
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Assigned to each finite element
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Values range from 0 to 1
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0 = material to be taken away
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1 = material to be kept
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Main Steps of Optimization Procedure
Define the structural problem
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Select the element types
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Specify optimized and non-optimized regions
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Define and control the load cases or frequency
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extraction
Define and control the optimization process
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Review the results
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Define the structural problem
Define the problem as you would for any linear
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elastic analysis
Single or multiple load case linear structural static analysis
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Modal frequency analysis
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Material properties to be defined
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Young’s modulus
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Poisson’s ratio
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Must be between 0.1 and 0.4
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Material density if necessary
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Element Types
2D Planar, 3D Solid, and shell
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elements are supported
2D Solids: PLANE2, PLANE82
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3D Solids: SOLID92, SOLID95
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Shells: SHELL93
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Only Type 1 elements optimized
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Used to control which regions of the model to optimize
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©2005 –IMPACT Engineering Solutions, Inc.
Primary Commands Used
TOCOMP
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Defines single or multiple load
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cases as topological optimization
function for linear static problem
TOFREQ
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Defines single or mean frequency
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formulation as the topological
optimization function for modal
analysis
TOVAR
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Specifies objective and
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constraints
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Primary Commands Used
TOTYPE
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Specifies solution method for
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topological optimization
TODEF
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defines the accuracy for the
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solution
TOLOOP
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Invokes a macro to solve, postprocess, and plot each iteration
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Process terminates once convergence is attained or the maximum iteration
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number is reached
Up to 100 iterations allowed
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