Nonlinear Stability Analysis Of Single Layer Lattice Shells With Complex Surface

The stability of lattice shells is a key issue for lattice shells,especially for single layer lattice shells with complex surface. The ultimate capacity of the spatial structures and the influences of various factors to stability are considered in this thesis.The article takes the steel structure of six complex surface of sunlight valley in the project of "World's fairs Axis" in Shanghai 2010 World' fairs as background. In order to studied the stability of the steel structure of lattice shells with six complex surface,geometry nolinear stability and geometry material double nolinear stability analysis are carried out. The analysis indicates that the overall structrue stability are satisfied by the related requirement of critical load coefficient of nonlinear buckling analysis,and the influence of vaious combinations of different loads is not obvious. The nolinear stability of sunlight valley steel structure reduced with the increase of initial impefection accordingly,but as a whole it is insensitive to the initial impefection. The ultimate capacity only considering the geometry material double nonlinear influence decreases comparing to that of the geometry nonlinear analysis.The influence of geometry initial impefection to stability of the sunlight valley steel structure is further studied by introducing the first eighth step buckling mode as the initial defect distribution form separately to carry on the geometry material double nolinear stability analysis, and the initial impefection sensitivity of single layer lattice shells with complex surface are further inspected.The influence of member's stability to the overall stability are studied, in this thesis The critical load is firstly obtained when some members starts to buckle, and the process of structure's buckling is got by modifing model gradually. It is concluded that the overall stability of the structrue will reduced obviously when structual member starts to buckle both in-plane and out-plane,but there is a little influence when the minority member's buckling.