Collapse-resistance optimization of fabricated single-layer grid shell based on sequential approximate optimization

Abstract

In this work, the surrogate model of the collapse load in terms of the structural morphology is established based on the radial basis function (RBF) network, and the form-finding optimization of the fabricated single-layer grid shell aiming at the improvement of collapse-resistance capacity is realized. To improve the accuracy of the optimal solution, the density function is used to determine the sparse region in the design domain and add new sample points in the sparse region. Avoiding that the optimization is trapped in a poor local optimum, the starting point is updated to approach the global optimum. Three types of fabricated single-layer grid shells, including cylindrical surface, free-form surface with symmetric supports, and free-form surface with asymmetric supports, are selected for form-finding optimization. The results prove the efficiency of the optimization algorithm. The proposed optimization method considers the mechanical properties of assemble joints and reflects the mechanical characteristics of the actual structure. It can be used for form-finding optimization and shape selection in structural design and thus has engineering significance.