Mechanical Engineering, Indian Institute of Science, Bangalore 560 012, India
Optimization hinders evolution!
ME256 Variational Methods and Structural Optimization Jan.-May, 2019
Instructor: G. K. Ananthasuresh, Room 106, ME Building, suresh at iisc.ac.in
Lectures: Tu, Th: 08:30 AM - 09:55 AM; Venue: ME MMCR

Schedule and Notes

Week Dates Topics Notes Assignments
1 Jan. 3: Panorama of optimization problems; scope of the course.
Lecture 1
Lecture 2
Homework 1
2 Jan. 8: Unconstrained minimization in finite number of variables: necessary and sufficient conditions
Constrained minimization with equality constraints: Lagrange multiplier concept
Necessary conditions for constrained minimization (two variables).
Jan. 10: Necessary conditions for constrained minimization (N variables).
Lecture 3
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3 Jan. 15: Sufficient conditions for constrained minimization; Bordered Hessian
Genesis of calculus of variations
Calculus of variations problems in geometry and mechanics
Jan. 17: Calculus of variations problems in geometry and mechanics (contd.)
Formulating calculus of variations problems.
KKTdemo.m (Example file for familiarity with KKT conditons)
obj.m (Objective function file)
g1.m (Nonlinear constraints file)
Lecture 4
Lecture 5, Lecture 6
Homework 2
4 Jan. 22: Mathematical preliminaries to calculus of variations: vector spaces and their properties; function spaces
Jan. 24: Mathematical preliminaries to calculus of variations (contd.): Gateaux variation
Lecture 7
Lecture 8
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5 Jan. 29: Frechet differential, Frechet derivative
Euler-Lagrange equations; How did Lagrange derive them? fundamental lemma of calculus of variations
Euler-Lagrange equations; How did Lagrange derive them? How did Euler derive them?
Variational derivative
Jan. 31: Extension of Euler-Lagrange equations to multiple derivatives; beam problem
Extension of Euler-Lagrange equations to multiple functions
Lecture 9
Lecture 10
Lecture 11
Homework #3
6 Feb. 5: Euler-Lagrnage equations when there are two independent variables of the unknown function.
Euler-Lagrange equations when there are three independent variables of the unknown function.
Feb. 7: Discussion on Gateaux variation, Frechet differential, Frechet derivative, and variational derivative; why and what we should know about Banach, Hilbert, and Sobolev spaces" Q & A on what is covered until now.
Lecture 12
Lecture 13
Homework #4
7 Feb. 12: Global (functional type) constraints in variational calculus
Local (point-wise or function type) constraints in variational calculus
Feb. 14: Variable end conditions in calculus of variations; Weierstrass-Erdmann corner conditions; broken extremals.
Lecture 14
Lecture 15
Homework #5
8 Feb. 19: First integrals of Euler-Lagrange equations; change of variables; parametric form; transformation with a parameter and Noether's theorm.
Feb. 21: "Inverse" Euler-Lagrange equations problem: going from the differential equation to the functional to be optimized: three methods, (i) for self-adjoint operators, (ii) integrating factor method for dissipative systems, and (iii) parallel generative system for dissipative cases.
Lecture 16
Lecture 17
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9 Feb. 26: Practice problems in calculus of variations Review of lecture material until now; Q&A

Feb. 28: Midterm examination; 1 h duration during the class-time; open-books, open-notes,open-Internet; interacting with any live person is not permitted.
Lecture 18
Midterm examination papers from 2005 to 2018
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10 Mar. 5: Bar optimization: stiffest bar for a given volume
Mar. 7: Bar optimization: Interpretation of boundary conditions; lower and upper bounds on the design variable; other objective function;
Lecture 19a
Lecture 19b
Bar optimization files
Homework #6
11 Mar. 12: Optimality criteria method; Matlab code for bar optimization
Beam optimization: stiffness for given volume;
Mar. 14: Bar and beam optimization: constraints on displacement, stress, etc.
Lecture 20
Beam optimization files
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12 Mar. 19: Mutual strain energy and design for deflection of a beam problem for indeterminate beams
Mar. 21: Class cancelled due to NCMDAO (optimization conference)
Lecture 20
Beam optimization files
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13 Mar. 26: Optimal design for deflection of beams for statically determinate beams
2D continuum; design for deflection
SIMP method for topology optimization
Mar. 28: 2D continuum and 3D continuum stiffness problems
Hierarchy in structural optimization: topolgy, shape, and size
FEA notes using the energy method
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14 Apr. 2: Demonstration of software YinSyn, TopOpt, etc.
Truss optimization
Sensitivity analysis: direct and ajoing methods
Apr. 4: Sensitvity analysis (contd.)
Stress constraints; transient loading; and multi-physics formulations
YinSyn files
TopOpt.m: 99-line Matlab code of O. Sigmund
99-line code paper of O. Sigmund
Truss FEA Matlab files
Transient loading sensitivity analysis
Electro-thermal-elastic structure problem
Homework #7
15 Apr. 9: Eigenvalue problems and their minimum characterization
Apr. 11: Raleigh quotient for eigenvalue problems
Optimization of a column for maximum buckling load
Minimum characterization of eigenvalue problems Strongest column Matlab code
Link to NPTEl lecture on stability analysis and buckling using calculus of variations
Link to NPTEL lecture on strongest most stable column
Homework #8
16 Apr. 22: Final examination 2 PM to 5 PM in ME MMCR
May 6 : Project presentations from 8:30 AM to 12 noon in ME MMCR
Previous years' final examination papers
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You can find the content-page of the previous years here.
2018
2017
2016
2015
2014
2013
2012
2011
2009
2007
2006
2005