Vibration tests and numerical simulation for a wheeled self-propelled gun chassis considering nonlinear damping characteristics of shock absorber

To study the effect of nonlinear damping feature of a shock absorber on the vibration of a wheeled self-propelled gun chassis during running firing, a shock absorber nonlinear damping model was built here based on the basic theory of fluid mechanics and hydraulic pressure. The damping coefficient and stiffness coefficient expressions of the shock absorber were deduced with its nonlinear damping characteristics included. In addition, according to the specific structural characteristics of a certain wheeled self-propelled gun, the expressions to calculate the equivalent damping coefficient and the equivalent stiffness one for the suspension of the gun were developed. The chassis vibration tests of the wheeled self-propelled gun during running firing were done. Based on the tests data and the theoretical studying, numerical modeling simulations for the damping and stiffness coefficients of the absorber with a linear expression and with a nonlinear one were done, respectively. The results showed that the simulation results with nonlinear damping and stiffness coefficients agree well with the test data, but there is a bigger error between those with linear damping and stiffness ones and the test data, so the damping and stiffness coefficients of the absorber have a great effect on the chassis vibration of the gun. The proposed method provided a reference for chassis vibration simulations of other guns.