A program is developed for the design sensitivity analysis and optimization of nonlinear truss structures. Geometric and material nonlinearities are considered with the updated Lagrangian formulation. Sensitivities for the stress, strain and displacement constraints are obtained through the direct differentiation method. Truss structures are optimized by the successive quadratic programming method without line search procedure.
Several truss structures are analized, whose sensitivities are in good agreement with those form the analytic solution and numerical differentiation and in the literature. The optimal designs are obtained for the structures within about 60 iterations and the results are in good agreement with those available. It is noted that the consideration of nonlinear behaviours makes the optimum more realistic and results in further redsuction in the overall weight.
