Mechanical Engineering, Indian Institute of Science, Bangalore 560 012, India
Optimization hinders evolution!
ME256 Variational Methods and Structural Optimization Jan.-May, 2016
Instructor: G. K. Ananthasuresh, Room 106, ME Building, suresh at mecheng.iisc.ernet.in
Lectures: Tu, Th: 08:30 AM - 09:55 AM; Venue: ME Lecture Hall

Schedule and Notes

Week Dates Topics Notes Assignments
1 Jan. 5: Panorama of optimization problems; scope of the course.
Unconstrained minimization in finite number of variables: necessary and sufficient conditions
Jan. 7: Constrained minimization with equality constraints: Lagrange multiplier concept
Lecture A
Lecture B
Lecture C
Homework #1
2 Jan. 12: Constraint qualification
Karush Kuhn-Tucker (KKT) conditions

Jan. 14: Sufficient conditions for a constrained minimum; Bordered Hessian

History of calculus of variations
Lecture D
Lecture E
-
3 Jan. 19: Calculus of variations in geometry and mechanics
Jan. 21: No class
Lecture F
Homework #2
4 Jan. 26: No class; Happy Republic Day!
Jan. 28: Functional, metric spaces, vectors spaces, norm, inner product, Banach space, Hilbert space, Lebesgue and Sobolev norms;
Significance of all of these in calculus of variations and structural optimization
Lecture G
Lecture H
Homework #3
4 Feb. 2: Gateux variation and Frechet differential; related concepts.
Fundamental lemma of calculus of variations
Euler-Lagrange equations
Feb. 4: Euler's way of deriving Euler-Lagrange's equations; variational derivative
Euler-Lagrange equation for a bar under axial loading; strain energy, work potential and the principle of minimum potential energy; principle of virtual work and the weak form
Lecture I
Lecture J
-
5 Feb. 9: Boundary conditions in calculus of variations Euler-Lagrange equations and their generalization to many derivatives and many functions
Integrals and invariants of Euler-Lagrange equations
Change of variables in Euler-Lagrange equations
Feb. 11: Noether's theorem (guest lecture by Prof. Ramsharan Rangarajan)
Lecture K
Lecture H
Noether theorem
Homework #4
6 Feb. 16: Functionals involving two or three independent variables.
Functionals with spatial and temporal variables
Feb. 18: Global (functional) constraints in calculus of variations
Lecture I
Lecture J
Homework #5
7 Feb. 23: Local (pointwise or continuous) constraints in calculus of variations
Feb. 25: General variation
Transversality conditions, broken extremals, and Weierstrass-Erdmann corner conditions
Obtaining the functional from the differential equation: self-adjointness, two methods for dissipative systems (integrating factor and parallel generative system)
Lecture K
Lecture L
Homework #6
8 Mar. 1: Stiffest bar for given volume; design and adjoint equations; uniformly stressed design
Mar. 3: Midterm examination
Past midterm papers
-
9 Mar. 8: Discussion of the midterm problems
Optimality criteria method
Mar. 10: Variants of the stiffest bar problem: switching the objective function and resource constraint, using the weak form of the governing equation; Clayperon's theorem;
Stiffest beam for given volume
-
-
10 Mar. 15: Upper and lower bounds on the design variables in the bar problem
Optimality criteria method for the bar
Stress constraints
Mar. 17: Optimization for flexibility
-
Homework #7
11 Mar. 22: Sensitivity analysis: continuous vs. discretized
Direct method vs. adjoint method
Mar. 24: Optimization for natural frequency
Eigenvalue equation for bars using Hamilton's principle
-
Homework #8
12 Mar. 29: Minimum characterization of eigenvalue problems
Rayleigh quotient
Mar. 31: Maximizing the frequency of a bar for given volume
-
-
13 Apr. 5: Buckling phenomenon from the energy and stability viewpoint
Derivation of the eigenvalue problem for column buckling and Rayleigh quotient
Most stable column for given volume of material
Apr. 7: Demonstration of bar, beam, and column optimization codes in Matlab using the optimality criteria method
Clarification on handling the inner loop and upper and lower bounds on area of cross-section variables.
Matlab code for stiffest bar optimization
Matlab code for stiffest beam optimization
Matlab code for most stable column optimization
Homework #9
14 Apr. 12: Structural optimization in a multiphysics problem--electro-thermal-elastic actuator optimization
Transient problem--sensitivity analysis
-
-
15 Apr. 20: Final Examination, 2 pm in the classroom
May 2: Project presentations starting at 8:30 am; 15 min for each person.
Final examination papers of past 11 years
-

You can find the content-page of the previous years here.
2015
2014
2013
2012
2011
2009
2007
2006
2005