Abstract:The bladder accumulator stores energy and stabilizes pressure changes in the form of compressing gas inside the rubber balloon during operation.Based on the ideal gas state equation and Mooney-Rivlin hyperelastic constitutive equation,the eigenvalue buckling analysis and the nonlinear post-buckling analysis of the finite element model of the fluid cavity of the bladder accumulator were carried out by linear perturbation and dynamic explicit simulation method.The results show:under the action of a uniform hydraulic load,the rubber balloon shows three pits deformed,which is consistent with the deformation in the experiment,indicating that the reason for the deformation of the three pits is buckling instability of the rubber balloon;the dynamic explicit simulation method solves the problems of poor calculation convergence and low calculation efficiency in the large deformation of rubber,and provides a good simulation method for the large deformation simulation of the three-dimensional solid model of rubber materials; the volume of the fluid cavity model of the rubber balloon is approximately inversely proportional to the pressure in the cavity,which is consistent with the ideal gas adiabatic equation,indicating that the use of fluid cavity to simulate the internal gas cavity of the rubber balloon is reliable.