Abstract: APDL,the re-development language of the common finite element analysis software ANSYS,was adopted as development tool.Member cross section areas of the grid structure were taken as the design variables.The total weight of the grid was considered as the objective function.The restrain conditions such as strength,stability,rigidity,deflection and cross section dimensions were considered.The improved one-dimensional search method and full-stress method were selected as the optimization method.The two steps,rigidity optimization and stress optimization,were taken as optimization process.The calculated results show that the optimal method has simple principle and good convergence rate.The result of Ansys can be directly used as the optimization of design.

Key words: grid structure, optimum design, APDL