Optimum Damping and Stiffness in a Nonlinear Four-Degree-of-Freedom System Subject to Shock Load

A nonlinear four-degree-of-freedom system representing an articulated off-road vehicle is analyzed for ground shock response. The assumed shock is a versed-sine pulse, which results as one front wheel passes over a ground surface bump. Families of exponential functions are used to represent the nonlinear stiffness and nonlinear damping. Digital computer solutions to the nonlinear differential equations of the system are obtained for combinations of different members of these families. Certain combinations are then selected which produce optimum responses; these responses are then compared to the optimum responses for linear systems.