유체 봉입 마운트의 동적 특성화를 위한 집중 질량 요소를 갖는 기계적 모형의 문제점 파악과 실험 방법 개선을 통한 수력학적 모형의 타당성 확인A Study on Shortcomings of Mechanical Model with Lumped Mass for Dynamic Characterization of Hydraulic Mounts and Confirmation of Hydraulic Model by Improvement of Experimentations
Hydraulic mounts show strongly frequency-dependent stiffness and damping characteristics in low frequency range, which result from so called inertia track dynamics. A lumped mass has been incorporated in several mechanical models of the literature to take the inertia effect of the fluid in the track into consideration. Although complex stiffness by the mechanical model showed good agreements with the measured values, there exists a critical pitfall. In this paper, the shortcomings of mechanical models with lumped mass for hydraulic mounts are clearly identified by illustrating actual measurements of the stiffness parameters for a hydraulic mount. It is conclusively discussed that the inertia effect of the fluid flow through the circular track is significant but latent. As an alternative to the mechanical model, a hydraulic model is claimed to be used for further dynamic analysis of engine/mount system or whole car system.