Dynamic Buckling Of Cylindrical Shells Under Combined Loading

Cylindrical shell is the most common structural form of shells. The buckling of cylindrical shells is playing an important role in structural stability, which has increased great development in the theories of structural stability. The dynamic buckling of cylindrical shells under both coupling impact and internal or external pressure is different from the dynamic buckling of the structure under coupling impact loading alone. Therefore, it is necessary to discuss dynamic buckling of structure under combined loading.The research of the structure under coupling loads has achieved lots of results and solved many practical problems, But, to solve the structure under combined loading is difficult. When the Hamiltonian system is introduced into the research of dynamic buckling, the problem uses dual variables in Symplectic space instead of variables in traditional Euclidean space. The symplectic eigenfunction expansion method gives out an exact solution space. So many problems are solved, which can not find the solution in traditional methods. In this paper, the fundamental problems of the dynamic buckling in cylindrical shells are axial impact, axial impact and radial pressure, coupling impact, coupling impact and radial pressure. Establish the Hamiltonian system and solve the critical buckling loads and buckling modes. The critical parameters have special forms according to characteristics of propagation and reflection of stress wave. The critical buckling loads and buckling modes have great changes under different boundary conditions. Discuss respectively cylindrical shell buckling characteristic with internal or external pressure.The numerical results show that the radial pressure and coupling impacting loads affect each other and determine the dynamic buckling cylindrical shells together. Compared with cylindrical shells under coupling impact, internal pressure drops the impact resistance ability and external pressure increases resistance capacity. The critical buckling loads and buckling modes have special forms that according to propagation and reflection of stress wave. Radial pressure makes the dynamic buckling process of cylindrical shells more complex. The practical project should fully consider its influence on the stability of cylindrical shell.