Multi-Physics Modeling of a Cab Suspension System with Fluid Filled Mounts

This paper presents a novel 6-DOF multi-physics model of a cab suspension system. The model consists of a cab with six degrees of freedom supported by four fluid filled viscous mounts. In the literature, to the best of the authors' knowledge, all 6-DOF cab models have simplified fluid filled mounts as spring damper combinations. In its best case, a nonlinear stiffness relationship is allowed in the simplified models to capture the nonlinear behavior of the mounts and include geometric constraints and hard-stops. The novel model presented in this paper, however, includes a multi-physics model of the mounts. Each mount is represented by a molded assembly, two fluid chambers, a fluid track that connects the two chambers, and a gas chamber. Each mount can be pressurized or vented. A simple cavitation model is also used as an indicator of fluid cavitation in each mount. Additionally, all acceleration terms including cross-coupled and normal component accelerations are included in the 6-DOF model. Therefore, all nonlinear effects in various translational and rotational directions can be studied. This comprehensive cab model allows design engineers to choose fluid filled mount design parameters and mounting locations using a global design tool. The effects of a few design parameters on the overall response of the cab are studied and presented.