索撑单层球面网壳多点地震输入下的失效特征研究

The arrangement of in-plane and out-of-plane cables in a two-way grid dome structure effectively enhances its stiffness and improves the bearing capacity. The seismic response and failure characteristics of a 60 m span cable-stiffened single-layer spherical reticular shell under uniform and multiple-support excitations with the consideration of the spatial variation of ground motion were analyzed. Based on the load displacement response at key nodes, the plastic proportion of the lattice shell member, and the damage degree of the latticed shell, the failure forms of the lattice shell structure under different seismic load excitation were investigated, and the dynamic failure mechanism of the single-layer spherical lattice shell structure was revealed. The results show that the in-plane and the out-of-plane cables effectively enhances the ductility of the lattice shell structure. Even if the reticulated shell has a large displacement, the structure still will not fail. The reticular shell members enter into plasticity from the four end areas under uniform excitation, while they will gradually enter into plasticity from the periphery support to the inner ring under multi-support excitation. Compared with the uniform excitation, the critical load of the two-way grid shell under multi-support excitation is greatly reduced. The failure forms of the reticular shell are all strength failure, and the strength failure characteristics under multi-support excitation are more obvious.