Modeling a 6-DOF elastomeric mount for frequency converter (FC) under different base excitations

Abstract

This study presents a six degrees of freedom (6-DOF) passive vibration isolation model using elastomeric mounts aimed at minimizing vibration transmission in Frequency Converters (FCs). The model features eight distinct elastomeric mounts to evaluate the response of the system to various dynamic loads, including shocks, sinusoidal base excitation, bumps, rotational unbalances, and their combinations. The analysis focuses on the impact of these loads on the Center of Gravity (CG) of the FC system. Additionally, the effects of offsetting the CG from the Geometric Center (GC) and inclining the principal elastic axis of the isolator away from the global coordinate axis are explored. The proposed analytical model is validated using the ISOMAG tool, specifically designed for vibration isolation studies. Results indicate that offsetting the CG induces cross-axis responses compared to the other configurations. Furthermore, inclining the isolators at a 25° angle demonstrates greater effectiveness in vibration reduction than maintaining them in a vertical position, achieving a maximum dissipation of vibration amplitudes by 44%, depending on the specific loading conditions applied.