摘要:A new algorithm is presented for size optimization of truss structures considering any kind of smooth objectives and constraints, together with constraints on the collapse loading obtained by limit analysis for loading conditions. The main di.culty of this problem is the fact that the collapse loading is a nonsmooth function on the design variables. In this paper we avoid nonsmooth optimization techniques. Our approach is based on a Feasible Directions Interior Point Algorithm for nonlinear constrained optimization. Three illustrative examples are discussed. The numerical results show that the calculation e.ort when limit analysis constraints are included is only slightly increased with respect to classic constraints.