| As one of the main forms of long-span spatial structure, spherical reticulated domes have been used widely, and they have become a landmark around. However, because of their specialty, great political and economic sense, the structures are easy to be attacked by natural disasters and human action. The impact loading is characterized by short time, ultra energy and large destructive power. Once attacked, the spherical reticulated domes can be seriously damaged as well as the negative influence on the society and psychological impact on people. Specifically, after the 9.11 incident, people have paid more attention to the performance of the structures under the impact load; and the study on shock response of spherical reticulated domes has become a hot issue nowadays.This paper describes the finite element analysis software ANSYS/LS-DYNA, the software used to solve the impact problems, and the basic theory of the software for solving this kind problem. Then, the modeling method of solving impact problem is explained. A reasonable simulation method of the structure under impact load is established by defining the proper element type, material properties and contact category. The method for analyzing the impact response is verified by a typical example.Based on the ANSYS/LS-DYNA software, the analysis for the 40m span geodesic spherical domes and Schwedler spherical domes under impact load is carried out. The three failure modes of the spherical domes are summed up: local structural depression, whole structural collapsed, shear failure of bar. The characteristics of the dynamic response of the structure with different failure mode, such as the impact load, speed of nodes, displacement of nodes, and stress of bars, are investigated.By changing the mass of impact object, impact velocity and impact location, the parametric analyses on the dynamic response of two kind shell structures under the impact loading are carried out. The effects of these parameters on the failure mode of the structures are investigated, and the distribution regularity of the failure modes of the structures with different parameters is explained in this paper. |
