Design Optimization of Automotive Engine Mount System

The highly competitive automotive business industry requires manufacturers to pay more attention to passenger comfort and riding quality. This has forced designers to direct their attention to the development of high quality engine mountings. The energy absorption characteristics of the engine mount are mainly influenced by two variables, the material and the design. In real world automotive manufacturing there is a fewer chances of the material changes for any subsystem as the material procurement is bulk order process. Hence the design of the engine mount becomes the critical aspect in terms of vehicle crashworthiness. In this particular study, different designs of the engine mount system have been evaluated for damageability starting from the base model. In the process of optimizing the damageability, study has been performed repetitively on engine mount with design configurations. In this work, special attention is given to the accurate modeling of nonlinear effects on the dynamic behavior of the engine mount using LS-Dyna simulation. Based on the finite element model created, the mounts frequency response function curves are determined and multi-dimensional effects in the mounts response are observed. Also, the engine mounts time dependent response is compared to the ones obtained using a damping material model suggested by the automotive constructors. The overall results indicate that the modeled engine mount i.e. Four arm symmetry has an acceptable performance in both isolating engine induced vibration and suppressing high amplitude engine shake movement. Finally, some remarks are made about the use of parallel associated rubbers and nonlinear dynamic properties as a mean for improving the mounts dynamic behavior.