Constrained quasiconvexity and structural optimization

We propose an approach to general structural optimization problems based on variational techniques. The analysis involves gradient Young measures in t he vector case and the notion of constrained quasiconvexity, and depends on the appropriate use of stream functions in dimension two. The case of seve ral nonlinear materials and arbitrary cost functionals depending on the gra dients of the equilibrium states can also be treated. This generality is th e main motivation for this work.