The purpose of this paper is to study dynamic buckling behaviors and dynamic characteristics of clamped shallow spherical caps under a hydrostatic pressure load and dynamical cyclic sine-wave pressure loads, aiming to analyze the stability for caps in nonconservative systems as dynamic random loads. In this nonlinear analysis it is used that the method based on both of the finite element method and the mode-superposition method. In the numerical study the following results were obtained. 1) There are two types of dynamic buckling mechanisms, the symmetric snap-through and the asymmetric bifurcation buckling mechanisms. 2) The dynamic bucking loads drastically decrease to be affected by the dynamic resonance on symmetrical modes. 3) The qualitative fluctuations of dynamic behavior, the appearance of dynamic buckling phenomena, occur by the change of the magnitude of static pressure loads.
