An algorithm based on Semi-Definite Programming (SDP) is proposed for the truss topology optimization problem for specified linear buckling load factor, and optimal topologies of trusses are computed by using the Semi-Definite Programming Algorithm (SDPA). It is well known that optimizing structures for specified buckling load factor is difficult because of non-differentiability of the buckling load factor for the case of multimodal solutions. It is shown, in the examples, that the proposed algorithm is applicable to multimodal cases, and an optimal topology with five-fold buckling load factors is found without any difficulty.
