Optimization of a layered spherical inclusion in a matrix in triaxial tension at infinity

We consider the problem of synthesis, from a finite set of elastic homogeneous isotropic materials, of a multilayered spherical inclusion of minimum weight in a matrix stretched at infinity by three different uniform axial forces, under given restrictions on the strength and thickness of the inclusion. Necessary optimality conditions have been obtained, a computational algorithm has been constructed, and an example of calculation of an optimum inclusion has been given.