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Virtual International Conference on Isogeometric Analysis, 2021

Bayesian shape optimization in high dimensional design spaces using IGA-enabled solvers

Shahroz Khan

Panagiotis Kaklis

Andrea Serani

Matteo Diez

CNR-INM, National Research Council -Institute of Marine Engineering, Rome, Italy

Department of Naval Architecture, Ocean and

Marine Engineering, University of Strathclyde Glasgow, UK

GRAPES

learninG, pRocessing And oPtimising shapES

Konstantinos Kostas

School of Engineering and Digital Sciences, Nazarbayev University, Nur-Sultan, Kazakhstan

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Virtual International Conference on Isogeometric Analysis, 2021

Motivation

Parameterisation

Design/search space

Design’s Performance Evaluation

Design Space Exploration

  • High computational cost

Simulation-Driven Optimization (SDO)

  • Rises exponentially with dimensionality

CFD/EFA

Optimisers

CAD tool

  • Objective: Combine IGA-based boundary element method with

Karhunen–Loève expansion → Dimensionality reduction

Bayesian optimisation → Reduce number of design evaluations

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Virtual International Conference on Isogeometric Analysis, 2021

Low-dimensional subspace

High-dimensional design space

Parametric ranges

Design parameters

Parent design

Dimension reduction

Sample parametric design space

Discretisation of Shape Modification Function

Sample subspace

Reproject high-dimensional design

Create NURBS Surfaces

Simplify designs (i.e., reduce DoF)

Evaluate designs using BEM-isogeometric analysis

Construct surrogate model

Dataset

 

Proposed Pipeline

Bayesian optimisation

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Virtual International Conference on Isogeometric Analysis, 2021

Results

DTMB Naval Ship Hull

 

  • Parameterised with 27 design parameters
  • PCA:

9000 uniformly distributed designs

Dimensionality reduces from 27 to 16

Geometric variance: 95.567%

 

  • PCA Results:
  • Optimisation Results:

Original

Optimised