Optimal limit design of elasto-plastic structures for time-dependent loading

A new approach is presented for the design of structures where the solution of the boundary value problem is approximated by an infinite function series of the state variables expressed in terms of time. Space discretization is used, but the state variables, ordered to the nodes, are continuous functions of time. In spite of a direct mathematical programming technique, the structural response to the time-dependent loading can be followed and the energy dissipation is considered. The design variables are the cross-sectional dimensions and the dissipative forces, and design constraints enforce upper bounds on the flexibilities.