Study on nonlinear stiffness characteristics of cystiform air spring

Based on the study of the mechanics features of air spring including the nonlinearities in material, geometry, contact, and with the method of nonlinear finite element analysis, the three-dimensional finite element model of a cystiform air spring was established. The analytical results were confirmed by the experiment with the use of an air spring test bench. The different contributions to the nonlinear stiffness characteristic of the cystiform air spring were studied in the paper, which related to the inflation pressure, capsule parameters and additional chamber volume. The results show that the inflation pressure, capsule cord angle and additional chamber volume of the air spring have distinct influence on the stiffness character; whereas, the number of capsule card layer, interval of capsule card grid, and capsule card material have a little impact.