Topological Optimization of Single-layer Spherical Shells with Genetic-simulated Annealing Algorithm

Taking the minimization of the structural weight as the optimization objective and using the rise f, the number of rings Nx and the cross-sectional dimensions Dixti of the members as the optimization variables, a topological optimization model for single-layer spherical shells is established. This model considers the constraints of slenderness ratio, deflection and member strength and stability to ensure that the optimized structure meets the requirements of codes and standards. Using Genetic Algorithm and Simulated Annealing Algorithm, a hybrid genetic-simulated annealing algorithm (GASA) is constructed. A GASA calculation program is coded using C++, and a GASA-ANSYS optimization program is developed by combining GASA program with ANSYS command stream coded using the APDL language. Finally, topological optimization of a K6 single-layer spherical shell with a 70-m span is performed using GASA-ANSYS. It is shown that the weight of the optimized structure clearly decreases compared with the original structure, and the limit peak ground acceleration of the shell before and after optimization are probably the same. Therefore, it is concluded that the optimization model and program can perform topological optimization of collapse scenarios for single-layer spherical shells subjected to severe earthquake excitation.