The RSM-based Optimization Framework for Singlelayer Latticed Shells with Prestressed Cables

The latticed shells with prestressed cables are typical hybrid structural systems with good mechanical performance and favorable economic benefits. A multi-objective optimization framework based on response surface methodology and the NSGA-II algorithm is proposed to improve the static, stability, and economic performance of single-layer latticed shells with prestressed cables simultaneously. The effectiveness of the optimal solution is verified by comparing its characteristic responses with the alternative solutions in the Pareto solution set. The efficiencies of the optimized shells with different cable layouts are compared, and the influence of joint stiffness is thoroughly discussed to guide practical design. The results indicate that the established response surface models have high accuracies for the nonlinear response optimization problem. The optimal solution has the best comprehensive performance in all the candidate solutions. For prestressed shells with different cable layouts, the optimized shell with only out-of-plane cables has the best economic performance, whereas the one with only in-plane cables has the best static performance. For latticed shells with different joint assumptions, the nonlinear buckling load and steel consumption are much greater in the optimized shells with semi-rigid joints due to the increased member section and length of the struts.