Mechanical Engineering, Indian Institute of Science, Bengaluru, 560 012, India
"The more you think, the less material you need"
ME260
Structural Optimization: Size, Shape, and Topology
Aug. 2024 to Nov. 2024
Instructor: G. K. Ananthasuresh, Room 106, ME Building, suresh at iisc.ac.in
Teaching assistant: To be decided, M2D2 lab in mecheng, someone at iisc.ac.in
Lectures: Tu, Th: 08:30 AM - 10:00 AM; Venue: ME MMCR

Timeline and lecture notes

Week Dates Topics Notes Others
1 - 6 Module 1: Structural design with finite-variable optimization
1 Aug. 6, 2024: Overview of the course (Size, shape and topology optimization)
Template of a structural optimization problem: What we need to learn and how to formulate problems
Identifying size, shape, and topology optimization problems
Aug. 8,2024: Finite variable optimization vs. calculus of variation; and how they relate to structural optimization
Lecture notes 1
Lecture notes 2
Lecture notes 2A
Lecture notes 3
Article on strctural hierarchy by Prof. Lakes
Article on Eiffel's optimal structures
2 Aug. 13, 2024: Unconstrained and constrained minimization
Aug. 15, 2024: No class due Independence Day
Lecture notes 4
Lecture notes 5
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3 Aug. 20, 2024: Constrained minimization; duality; two-bar truss optimization
Aug. 22, 2024: Multi-bar truss optimization
Lecture notes 6
Lecture notes 6 extra (duality)
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4 Aug. 27, 2024: Size (and topology) optimization of trusses and the optimality criteria algorithm
Aug. 29, 2024: Dual formulation of truss optimization for statically determinate trusses
Concepts of states of self stress and Maxwell's rule
Simultaneous geoemtry and material optimization of trusses
Lecture notes 7a
Lecture notes 7b
Lecture notes 8a
FEA theory notes (trusses and beams)
Matlab truss analysis code
Matlab truss optimization code
5 Sep. 3, 2024: Dual formulation of truss optimization for statically determinate trusses
Concepts of states of self stress and Maxwell's rule
Sep. 5, 2024: Dual method for truss optimizaition
Lecture notes 8b
Dual truss opt code
6 Sep. 10, 2024: Simultaneous geoemtry and material optimization of trusses
Sep. 12, 2024: Discusison of Homework 1, problem 1
Overview of the programming assignment 1
Summary of Module 1.
Lecture notes 9
Geometry+material optimization paper
Geometry+material statically-determinate truss optimization paper
7 - 11 Module 2: Structural optimization in the framework of calculus of variations
7 Sep. 17, 2024: Genesis of calculus of variations
Formulating variational problems in geometry and mechanics
Mathematical preliminaries of calculus of variations: vectors spaces, function spaces, etc.
Sep. 19, 2024: Gateaux (first) variation, Frechet differential, etc.
Fundamental lemma of calculus of variations
Some examples to practise taking variation
Fundamental lemma of calculus of variations
Genesis of calculus of variations
Geometry and mechanics problems cast as calculus of variations problems
Mathematical preliminaries to calculus of variations; functional and function spaces
Banach, Sobolev, etc., spaces
Read Ted Chiang's "Story of Your Life".
Try to watch Arrival, the movie, if you can find the time.
8 Sep. 24, 2024: Some discussion on definitions of functional spaces
The concept of variation and its mathematical interpretation
Distinguishing Gateaux variation, Frechet differential, and Frechet derivative
Fundamental lemma of calculus of variations.
Sep. 26, 2024: Variational derivative and derivation of Euler-Lagrange equations in the manner apparently done by Euler without using the concept of variation
Static equilibrium of a beam and interpreting the boundary conditions.
First variation of a functional
Fundamental lemma of calculus of variations
Euler-Lagrange equations in multiple functions and multiple derivatives but in a single domain variable
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9 Oct. 1, 2024: Examples of a bar and a beam static equilibrium equations
Three ways of writing static equilibrium: minimum potential energy, principle of virtual work, and force balance
Three ways for dynamic equilibrium: Hamilton's principle, D'Lambert's principle, and Newton's second law.
Dynamic equilibrium of a bar to motivate functionals of two independent variables.
Oct. 3, 2024: Euler-Lagrange equations when there are two and three independent variables
Euler-Lagrage equations with global (functional) and local (function) constraints
Two examples: Compliant design problem of a beam and contact problem with a beam
Euler-Lagrange equations in two and three independent variables
Euler-Lagrange euqations for global (or functional) constraints
Euler-Lagrange euqations for local (or function) constraints
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10 Oct. 8, 2024: Optimization of a bar (a dozen problems)
Bar optimization code in Matlab and the optimality criteria algorithm
Oct. 10, 2024: Beam optimization problem for stiffness, strength, and flexibility
Beam optimization code in Matlab
2D frame optimization
A dozen optimization problems of a bar
Solutions of two bar optimization problems
Many beam optimization problems
Solution to beam optmization for stiffness and flexibility
2D frame optimization problem
Beam optimization for strength
Bar optimization code
Beam optimization code
11 Oct. 15, 2024: Midterm examination: open-everything including the internet.
Oct. 17, 2024: Variable end conditions in Calculus of Variations; transversality conditions; broken extremals; Weirstrass-Erdmann conditions
Examples: Fermat's refraction problem and the generalization of the tractrix problem
Variable end conditions of a functional
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12 Oct. 22, 2024: Homogenization method and its role in topology optimization; 1D homogenization using asymptotic expansion method
Power law and material interpolation, and SIMP
Taking variation with vector and other shorthand notation
Playing with 99-line code to understand the influence of the penalty parameter and sensitivity filter
Practice with YinSyn code for stiff structures and compliant mechanisms
Oct. 24, 2024: Review of module 2 and an overview of Programming Assignment 2
Taking variation when there is shorthand notation with vectors
Homogenization of a 1D problem
99-line code for 2D stiff-structure optimization
YinSyn 2D code for topology optimization of structures and compliant mechanisms
13 - 16 Module 3: Multiphysics design problems; Sensitivity analysis for shape and topology optimization
13 Oct. 29, 2024: Pressure load problem and electro-thermal-elastic problem
Ananlytical expressions for sensitivity in the Calculus of Variations framework
Oct. 31, 2024: Material-property interpolation for topology optimization for electro-elasto-statics, fluids, etc.
Papers sent by email as a zip file.
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14 Nov. 5, 2024: Sensitivity of dynamic compliance; electro-thermal-elastic analysis
Reversal of the sequence of design sensitivity of adjoint variables in electro-thermal-elastic problems
Nov. 7, 2024: Verification of sensitivity using finite-difference methods and its pitfalls and a remedy
COMSOL overview; and demonstration of topology optimization using COMSOL
Coupled electrostatic and elastostatic problem
Topology optimization of coupled electrostatic and elastostatic problem
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15 Nov. 12, 2024: Sensitivity analysis: parameter, shape; 1D and 2D; Jacobian and its derivatives (material and space derivatives)
Nov. 14, 2024: Shape sesitivity and shape optimization
Parameter sensititvity of a functional
Shape derivative with a 1D example
Derivatives of the Jacobian and its other forms
Shape optimization in 2D
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16 Nov. 19, 2024: Numerical optimization techniques for topology optimization
Convex linearization leading to the method of moving asymptotes (MMA)
Nov. 21, 2024: Topological derivatives and their use
Discussion for project, term paper; course overview
Numerical optimization techniques
ConLin, MMA, and GCA papers
Topological derivative
Optimization with topological derivative
Instructions for the term paper
Project presentation template
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Schedule of lectures in previous years

Lecture notes of 2023 offering of this course

Lecture notes of 2022 offering of this course

Lecture notes of 2021 offering of this course

Lecture notes of 2020 offering of this course