Transient response evaluation of a hydraulic engine mount

The transient response of a typical hydraulic engine mount has been studied using analytical and experimental methods. First, a lumped parameter nonlinear model is used to formulate the problem and to suggest parameters that must be experimentally determined. Several configuration related to inertia track and decoupler are analyzed. Next, two bench experiments are constructed for the identification of nonlinear chamber compliances (with a without preloads) and non-linear fluid resistances. The nonlinear characteristics of the decoupler are described to accurately predict the time events of the decoupler gap opening and closing. An equivalent viscous damper model is employed along with a multistaged switching mechanism. Nonlinear behavior caused by the vacuum formation in the top chamber is studied by defining a bilinear asymmetric stiffness curve. All governing equations are then solved in the time domain to yield responses when step up, step down or triangular displacement waveforms are applied. New transient experiments were also conducted with an elastomer test system by applying known displacement inputs. Measured transmitted force and top chamber pressure signals were analyzed in the time and frequency domains. Results of the proposed simulation model match well with measured data.