扁球壳在热-机械荷载作用下的稳定性分析
摘要
Based on the geometric nonlinear theory for shallow shells, with the virtual work principle and the variational method, the displacement-type geometric nonlinear governing equations for shallow spherical shells in uniform temperature field under uniform external pressure were derived. With the shooting method, the numerical results of axisymmetric bending deformation of the shallow spherical shell in the immovable simply supported boundary condition were obtained. The critical geometric parameters were defined. The effects of various shell geometric parameters on the equilibrium paths and the critical loads were investigated. It is found that the upper critical load increases but the lower critical load first increases in a small range and then decreases with the geometric parameter in the range beyond its critical value. The effects of different values of the uniform temperature on the shell critical geometric parameter, the critical load and the equilibrium configurations were investigated under a given geometric parameter. Rise of the uniform temperature brings obvious increase of the upper critical load and obvious decrease of the lower critical load and the critical geometric parameter.