OPTIMIZATION OF ADAPTIVE TRUSS STRUCTURES USING THE FINITE ELEMENT FORCE METHOD BASED ON COMPLEMENTARY ENERGY

A structural analysis and optimization method is developed to find the optimal topology of adaptive determinate truss structures in the presence of various loading conditions. The objective function is based on the maximization of the structural strength subject to geometric constraints. The structural analysis is based on the finite element force method using the complementary strain energy and the optimization procedure is based on the Sequential Quadratic Programming (SQP) method. Equilibrium equations are satisfied a priori and compatibility conditions are derived through minimization of the complementary energy, which allows the calculation of element forces without explicitly generating the compatibility conditions. Additionally, the selection of the redundant members has been automated through the Gauss elimination technique. The proposed method has performed well and it is extremely efficient in geometry optimization of adaptive truss structures where the primary design variables are the active member forces.