Machine Tool Optimization with ANSYS optiSLang - Dynardo Gmbh · Machine Tool Optimization with...
Transcript of Machine Tool Optimization with ANSYS optiSLang - Dynardo Gmbh · Machine Tool Optimization with...
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Machine Tool Optimization with ANSYS optiSLang
© Dynardo GmbH
Outline • Introduction
• Process Integration
• Design of Experiments & Sensitivity Analysis
• Multi-objective Optimization
• Single-objective Optimization
• Summary
Thomas Most Dynardo GmbH
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Machine Tool Optimization with ANSYS optiSLang
• CAE-based virtual prototyping needs significant computational resources
• Physical phenomena may be coupled, non-linear and high dimensional
• Need to deal with failed designs (design creation, meshing or simulation may fail, license failure)
• Need to deal with many parameters (at least in the uncertainty domain)
Real world CAE-Applications
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Machine Tool Optimization with ANSYS optiSLang
optiSLang
• is an general purpose tool for variation analysis using CAE-based design sets (and/or data sets) for
the purpose of
• sensitivity analysis
• design/data exploration
• calibration of virtual models to tests
• optimization of product performance
• quantification of product robustness and product reliability
• Robust Design Optimization (RDO) and Design for Six Sigma (DFSS)
serves arbitrary CAX tools with support of process
integration, process automation and workflow
generation
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Machine Tool Optimization with ANSYS optiSLang
• optiSLang is an integration toolbox for
Process automation,
Design variation,
Sensitivity analysis,
Optimization,
Robustness evaluation,
Reliability analysis and
Robust design optimization (RDO)
• Functionality of stochastic analysis to
run real world CAE-based industrial
applications
Easy and safe to use:
• Predefined workflows,
• Algorithmic wizards and
• Robust default settings
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Excellence of optiSLang
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Machine Tool Optimization with ANSYS optiSLang
Example: Machine Tool Device
• Robotic system for drilling large
structural components
• Rating of robot kinematics and
machining quality
• Test device is used as a dummy
for large structural components
• High stiffness and light weight
(because of manual adjustment)
are required
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Fraunhofer IPA Stuttgart Germany
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Machine Tool Optimization with ANSYS optiSLang
Example: Optimization Task
Objective functions
• Minimization of mass
• Minimization of deformation
of the beam structure
for a positioning in
0°, 90° and 180°
Initial Design
• Mass: 207,2 kg
• Deformations:
• 0°-position: 0,12 mm
• 90°- position : 0,10 mm
• 180°- position : 0,07 mm
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Machine Tool Optimization with ANSYS optiSLang
Example: Simulation Model
• Three load cases in
ANSYS Workbench
• Deformations of 3 load cases
as outputs in parameter set
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Machine Tool Optimization with ANSYS optiSLang
Example: Optimization Parameters
• Thickness of upper plate (initial: 10 mm)
• Width, height and thickness of upper beams (50 x 50 x 3 mm³)
• Width, height and thickness of middle beams (40 x 40 x 3 mm³)
• Width, height and thickness of lower beams (70 x 70 x 4 mm³)
• Steel beam structure and upper plate is Aluminium
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Machine Tool Optimization with ANSYS optiSLang
© Dynardo GmbH
Process Integration Parametric model as base for
• User-defined optimization (design) space
• Naturally given robustness (random) space
Design variables Entities that define the design space
Response variables Outputs from the system
The CAE process Generates the results according to the inputs
Scattering variables Entities that define the robustness space
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Machine Tool Optimization with ANSYS optiSLang
optiSLang Integrations & Interfaces
Direct integrations ANSYS Workbench MATLAB Excel Python SimulationX
Supported connections ANSYS APDL Abaqus Adams AMESim LS-Dyna …
Arbitary connection of text-based solvers
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Machine Tool Optimization with ANSYS optiSLang
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ANSYS Workbench optiSLang Plugin • optiSLang modules connect directly to
ANSYS Workbench parameter set
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Machine Tool Optimization with ANSYS optiSLang
CAX-Interfaces – the ANSYS Workbench Node
• optiSLang Integrations provides the flexibility to extend the process chain
• ANSYS Workbench can be coupled with different other solvers
like MATLAB, SimulationX or Abaqus
• External geometry or mesh generators can work together with
the ANSYS Workbench node
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Machine Tool Optimization with ANSYS optiSLang
Automatic workflow
with a minimum of solver runs to:
• identify the important parameters for each response
• Generate best possible metamodel (MOP) for each response
• understand and reduce the optimization task
• check solver and extraction noise
Sensitivity Analysis Understand the most important input variables!
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Machine Tool Optimization with ANSYS optiSLang
Solver
Sensitivity Evaluation
• Correlations • Variance-based quantification
Regression Methods
• 1D regression • nD polynomials
• Sophisticated metamodels
Design of Experiments
• Deterministic • (Quasi-)Random
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Sensitivity Analysis Flowchart
1. Design of Experiments generates a specific number of designs which are all evaluated by the solver
2. Regression methods approximate the solver responses to understand and to assess its behavior
3. The variable influence is quantified using the approximation functions
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Machine Tool Optimization with ANSYS optiSLang
Deterministic DoE
• Complex scheme required to detect multivariate dependencies
• Exponential growth with dimension
• Full factorial:
• Koshal linear:
Advanced Latin Hypercube Sampling
• Reduced sample size for statistical estimates
compared to plain Monte Carlo
• Reduces unwanted input correlation
How to Generate a Design of Experiments
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Machine Tool Optimization with ANSYS optiSLang
• Approximation of response variables as
explicit function of all input variables
• Approximation function can be used for
sensitivity analysis and/or optimization
• Global methods (Polynomial
regression, Neural Networks, …)
• Local methods (Spline interpolation,
Moving Least Squares, Radial Basis
Functions, Kriging, …)
• Approximation quality decreases with
increasing input dimension
• Successful application requires
objective measures of the
prognosis quality
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Response Surface Method
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Machine Tool Optimization with ANSYS optiSLang
Metamodel of Optimal Prognosis (MOP)
• Objective measure of prognosis quality
• Determination of relevant parameter subspace
• Determination of optimal approximation model
• Approximation of solver output by fast
surrogate model without over-fitting
• Evaluation of variable sensitivities
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Machine Tool Optimization with ANSYS optiSLang
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The Sensitivity Wizard
• Drop the sensitivity wizard on the final solver chain
• Define the lower and upper bounds of the input variables
• The sampling method and sample number is recommended depending on the chosen solver runtime and number of parameters
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Machine Tool Optimization with ANSYS optiSLang
Example: Definition of Parameter Bounds
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Machine Tool Optimization with ANSYS optiSLang
Example: Design of Experiments
• 200 Latin Hypercube Samples
• 6 failed designs due to conflicting geometry parameters (red, violet)
• 16 designs with implausible model behavior (orange)
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Machine Tool Optimization with ANSYS optiSLang
Example: MOP Results
• All responses can be explained very well
• Mass is almost linear, deformations are nonlinear but monotonic
w.r.t. the input parameters
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Machine Tool Optimization with ANSYS optiSLang
Example: Influence of Parameters
• Thickness of upper plate is most
important for the mass
• Parameters of lower beam
sections have highest
influence on deformations
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Machine Tool Optimization with ANSYS optiSLang
Optimization
using MOP
Optimization Optimize your product design!
Start
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• Work with the reduced subset of only important parameters
• Pre-optimization on meta-model (one additional solver run)
• Optimization with cutting edge algorithms
• Decision tree for optimization algorithms
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Machine Tool Optimization with ANSYS optiSLang
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optiSLang Optimization Algorithms: concepts
Gradient-Based Methods
• Go downhill
• In the context of black-box solver gradient
needs to be measured via DoE schemes
Adaptive Response Surface Method
• DoE and surface fit
• Scanned area shifts and shrinks
Nature-Inspired Optimization
• Inspiration sources: evolution, swarm motion, thermodynamics, state insects
• Mutation, recombination, selection, propagation, … go beyond nature by
tthinking in operators
Start
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Machine Tool Optimization with ANSYS optiSLang
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optiSLang Optimization Algorithms: applications
Gradient-based Methods
• Clear favorite if objective function smooth and without local minima
• Repeated local search as strategy when there are few local minima
Adaptive Response Surface Method
• ARSM is the default choice
• Balance between robustness and efficiency
• Best if dimension<20
Nature inspired Optimization
• Recommended for global search
• Widest applicability (binary or discrete parameters, …)
• Realize optimization potential also in challenging situations
Start
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Machine Tool Optimization with ANSYS optiSLang
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The Multi-Objective Optimization Task
• Several optimization criteria are
formulated in terms of the input
variables x
• Uncountable set of solutions, if
criteria are contradicting
Balanced compromise is wanted
Scan of the Pareto-front as decision base
• Constraint restrictions are possible
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Machine Tool Optimization with ANSYS optiSLang
© Dynardo GmbH
Decision Tree for Optimizer Selection
Recommendation of most suitable optimizer depending on
Number and type of input parameters (automatic)
Number of constraints and objectives (automatic)
Analysis status (user setting)
Amount of failed designs (user setting)
Solver noise (user setting)
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Machine Tool Optimization with ANSYS optiSLang
Example: Definition of Optimization Criteria
• Goal 1: Minimization of the mass (initial 207 kg)
• Goal 2: Minimization of maximum deformation
in 0°, 90° und 180° position (initial 0.12 mm)
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Machine Tool Optimization with ANSYS optiSLang
Example: Multi-Objective Optimization using MOP
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Machine Tool Optimization with ANSYS optiSLang
Example: Multi-Objective Optimization using MOP
• As compromise solution a maximum deformation of 0.1 mm is chosen
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Machine Tool Optimization with ANSYS optiSLang
Example: Optimization using the MOP
• Optimization goal: minimization of the mass
• Constraints: Deformations (0°, 90° und 180°) smaller as 0,1mm
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Machine Tool Optimization with ANSYS optiSLang
Example: Optimization using the MOP
• Validated best design violates the constraints slightly
• Validated mass is larger as approximated
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Machine Tool Optimization with ANSYS optiSLang
Initial Design
• Mass: 207,2 kg
• Deformations:
• 0°-position: 0,120 mm
• 90°- position : 0,097 mm
• 180°- position : 0,067 mm
Optimized Design
• Mass: 184,7 kg (-11%)
• Deformations:
• 0°- position : 0,106 mm (-12%)
• 90°- position : 0,087 mm
• 180°- position : 0,060 mm
Example: Optimization using the MOP
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Machine Tool Optimization with ANSYS optiSLang
Example: Optimization using the FEM model
• ARSM optimizer using the previous optimum as start design
• Deformation constraints are fulfilled
• Mass is increased
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Machine Tool Optimization with ANSYS optiSLang
Initial Design
• Mass: 207,2 kg
• Deformations:
• 0°-position: 0,120 mm
• 90°- position : 0,097 mm
• 180°- position : 0,067 mm
Optimized Design
• Mass: 188,3 kg (-9%)
• Deformations:
• 0°- position : 0,100 mm (-17%)
• 90°- position : 0,084 mm
• 180°- position : 0,055 mm
Example: Optimization using the FEM model
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Machine Tool Optimization with ANSYS optiSLang
© Dynardo GmbH
• Sensitivity analysis helps to better
understand the physical phenomena and
to check or validate the simulation model
• Indification of important parameters helps
to significantly simplify and accelerate the
optimization task
• MOP-approximation can be used for fast
pre-optimization step or
multi-objective case studies
Summary
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Machine Tool Optimization with ANSYS optiSLang
Need more information?
Support &
trial license: [email protected]
Training: [email protected]
www.dynardo.de