E-Book, Englisch, Band 7, 222 Seiten, eBook
Gao / Xiao Isogeometric Topology Optimization
1. Auflage 2022
ISBN: 978-981-19-1770-7
Verlag: Springer Singapore
Format: PDF
Kopierschutz: 1 - PDF Watermark
Methods, Applications and Implementations
E-Book, Englisch, Band 7, 222 Seiten, eBook
Reihe: Engineering Applications of Computational Methods
ISBN: 978-981-19-1770-7
Verlag: Springer Singapore
Format: PDF
Kopierschutz: 1 - PDF Watermark
This book provides a systematic description about the development of Isogeometric Topology Optimization (ITO) method using the density, and then addresses the effectiveness and efficiency of the ITO method on several design problems, including multi-material structures, stress-minimization structures, piezoelectric structures and also with the uniform manufacturability, ultra-lightweight architected materials with extreme bulk/shear moduli, auxetic metamaterials and auxetic meta-composites with the NPRs behavior in microstructures. A detailed MATLAB implementation of the ITO method with an in-house code “IgaTop” is also presented.
Zielgruppe
Research
Autoren/Hrsg.
Weitere Infos & Material
1 Introduction 11.1 Topology optimization (Top-opt) 11.2 IsoGeometric Analysis (IGA) 31.3 Isogeometric Topology Optimization (ITO) 51.3.1 Density-based ITO methods 51.3.2 Level-set-based ITO methods 91.3.3 MMC/Vs-based ITO methods 111.4 Applications of topology optimization 121.4.1 Multi-material structures 121.4.2 Stress-related designs 141.4.3 Piezoelectric structures 161.4.4 Architected materials 181.4.5 Auxetic meta-materials/composites 201.5 Implementations of topology optimization 211.6 The main focus of the current monograph 222 The Density-based ITO method 252.1 NURBS-based IGA for numerical analysis model 252.1.1 NURBS basis functions 252.1.2 Galerkin’s Formulation for elastostatics 272.2 Density Distribution Function (DDF) for topology description model 282.2.1 NURBS for structural geometry 282.2.2 Density Distribution Function ( 302.2.3 Material interpolation model 332.3 The ITO formulations for two problems 342.3.1 ITO formulation for the stiffness-maximization 342.3.2 ITO formulation for compliant mechanism design 352.4 Numerical implementations 362.5 Numerical examples 372.5.1 Several numerical examples in 2D 382.5.2 Several numerical examples in 3D 442.5.3 Discussions on the smoothing mechanism 472.6 Discussions on the indispensability of the ITO method 48II2.6.1 Problems in the classic SIMP method ........................................................................................................................................ 482.6.2 The extension of the DDF ............................................................................................................................................................................ 512.6.3 Comparisons between the ITO and the FEM-based three-field SIMP...................................... 522.6.4 Numerical examples .............................................................................................................................................................................................. 532.7 Appendix for sensitivity analysis .................................................................................................................................................................... 622.8 Summary .............................................................................................................................................................................................................................................. 643 The Multi-material ITO (M-ITO) method ............................................................................................................................................................ 663.1 NURBS-based Multi-Material Interpolation (N-MMI) ................................................................................................ 663.1.1 The Field of Design Variables (DVF) ........................................................................................................................................ 663.1.2 The Field of Topology Variables (TVF) .................................................................................................................................. 663.1.3 Multi-material interpolation model .............................................................................................................................................. 673.2 Multi-material Isogeometric Topology Optimization (M-ITO) ........................................................................ 693.3 Design sensitivity analysis ........................................................................................................................................................................................ 703.4 Numerical examples in 2D ........................................................................................................................................................................................ 733.4.1 Two-materials design .......................................................................................................................................................................................... 743.4.2 Three-materials design ...................................................................................................................................................................................... 783.4.3 Discussions on the stiffness-to-mass ratio .......................................................................................................................... 823.4.4 Quarter annulus .......................................................................................................................................................................................................... 833.5 Numerical examples in 3D ........................................................................................................................................................................................ 853.6 Summary .............................................................................................................................................................................................................................................. 874 The ITO for stress-minimization problems .......................................................................................................................................................... 884.1 The problem of boundary stress concentrations ...................................................................................................................... 884.2 Topology description model .................................................................................................................................................................................... 894.3 NURBS-based IGA for stress computation .................................................................................................................................... 914.4 Induced aggregation formulations of p-norm and KS ...................................................................................................... 934.5 ITO for stress-minimization designs .......................................................................................................................................................... 964.5.1 Stress-minimization design formulation .................................................................................................................................. 964.5.2 Design sensitivity analysis .......................................................................................................................................................................... 974.5.3 Numerical implementations .................................................................................................................................................................. 1014.6 Numerical examples ........................................................................................................................................................................................................ 1014.6.1 Discussions on aggregation formulations of p-norm and the induced p-norm ...... 1034.6.2 Discussions on aggregation formulations of KS and the induced KS .................................... 1094.6.3 Discussions on the problem of boundary stress concentrations .................................................... 1124.6.4 Discussions on threshold projection ........................................................................................................................................ 1144.6.5 Discussions on the utility of the ITO ........................................................................................................................................ 1154.6.6 AM for experiment validations .......................................................................................................................................................... 1204.7 Summary .......................................................................................................................................................................................................................................... 121III5 The ITO for piezoelectric structures with manufacturability .......................................................................................... 1235.1 NURBS-based IGA for piezoelectric materials .................................................................................................................... 1235.1.1 Piezoelectric constitutive relations ............................................................................................................................................ 1235.1.2 IGA formulation for piezoelectric materials ................................................................................................................ 1245.2 Density distribution function with erode-dilate operators .................................................................................... 1255.3 Interpolation schemes of piezoelectric materials ................................................................................................................ 1275.4 ITO and RITO for piezoelectric actuators .................................................................................................................................... 1285.4.1 ITO formulation without manufacturability .................................................................................................................. 1285.4.2 RITO formulation with uniform manufacturability ............................................................................................ 1295.5 Sensitivity analysis ............................................................................................................................................................................................................ 1305.6 Numerical examples ........................................................................................................................................................................................................ 1325.6.1 The optimization of piezoelectric actuators using the ITO .................................................................... 1335.6.2 The optimization of piezoelectric actuators using the RITO ................................................................ 1375.7 Summary .......................................................................................................................................................................................................................................... 1436 The ITO for architected materials .................................................................................................................................................................................. 1456.1 Numerical implementations of the homogenization using IGA .................................................................. 1456.2 ITO for micro-architected materials ...................................................................................................................................................... 1476.3 Design sensitivity analysis .................................................................................................................................................................................... 1486.4 Optimality Criteria ............................................................................................................................................................................................................ 1496.5 Numerical examples ........................................................................................................................................................................................................ 1506.5.1 2D micro-architected materials ...................................................................................................................................................... 1516.5.2 3D micro-architected materials ...................................................................................................................................................... 1586.5.3 Prototypes using 3D printing .............................................................................................................................................................. 1636.6 Summary .......................................................................................................................................................................................................................................... 1647 The ITO for auxetic metamaterials .............................................................................................................................................................................. 1667.1 The ITO formulation for auxetic metamaterials .................................................................................................................. 1667.2 Design sensitivity analysis .................................................................................................................................................................................... 1677.3 A relaxed OC method .................................................................................................................................................................................................... 1687.4 Numerical examples ........................................................................................................................................................................................................ 1707.4.1 2D auxetic metamaterials ........................................................................................................................................................................ 1717.4.2 Discussions of the weight parameter ...................................................................................................................................... 1747.4.3 3D auxetic metamaterials ........................................................................................................................................................................ 1767.4.4 Simulating validation based on ANSYS .............................................................................................................................. 1827.5 Summary .......................................................................................................................................................................................................................................... 1858 The M-ITO for auxetic meta-composites ............................................................................................................................................................ 1868.1 The computational design framework.................................................................................................................................................. 1868.2 The M-ITO formulation for auxetic meta-composites ................................................................................................ 188IV8.3 Design sensitivity analysis .................................................................................................................................................................................... 1898.4 Numerical implementations ................................................................................................................................................................................ 1928.5 Numerical examples ........................................................................................................................................................................................................ 1928.5.1 2D auxetic composite with two materials ........................................................................................................................ 1938.5.2 2D auxetic composite with three materials .................................................................................................................... 2008.5.3 3D auxetic composite with two materials ........................................................................................................................ 2048.5.4 Simulating validations based on ANASYS ...................................................................................................................... 2128.6 Summary .......................................................................................................................................................................................................................................... 2179 An in-house MATLAB code of “IgaTop” for the ITO method ...................................................................................... 2189.1 A 56-line MATLAB code for the main function IgaTop2D ................................................................................ 2209.2 Geom_ModGeom_Mod: Construct geometrical model using NURBS .................................................................................. 2219.3 Pre_IGAPre_IGA: Preparation for IGA.................................................................................................................................................................... 2249.4 Boun_CondBoun_Cond: Define Dirichlet and Neumann boundary conditions .................................................... 2289.5 Initialize control densities and the DDF at Gauss quadrature points .................................................... 2299.6 Shep_FunShep_Fun: Define the smoothing mechanism .................................................................................................................. 2319.7 IGA to solve structural responses ................................................................................................................................................................ 2319.7.1 Stiff_Ele2D ...................................................................................................................................................................................................................... 2329.7.2 Stiff_Ass2D ...................................................................................................................................................................................................................... 2349.7.3 Solving .................................................................................................................................................................................................................................... 2359.8 Objective function and sensitivity analysis .................................................................................................................................. 2369.9 OCOC: Update design variables and DDF .............................................................................................................................................. 2379.10 Plot_DataPlot_Data and Plot_Topy: Plot_Topy: Representation of numerical results ........................................ 2389.11 Demos for several examples .............................................................................................................................................................................. 2409.12 Summary .......................................................................................................................................................................................................................................... 242References .............................................................................................................................................................................................................................................................................. 243




