Prediction of Engine Mount Vibration using Multi Body Simulation with Finite Element Models

This paper discusses the prediction method of engine mount vibration using multi body simulation (MBS) with FE models in power plant assembly. In this analysis, some parts of the power plant were modeled with shell type elements and solid type elements, and modal parameters from FEA were imported into MBS, which method is called “Component Mode Synthesis”. For this analysis, the computational models of Suzuki 660cc in-line 3-cylinder engine with 4-speed automatic transmission were used. The flexibility of some engine parts was considered using FE models regarding the cylinder block, the crankshaft, the transmission case, etc. Also the properties of stiffness and viscous damping of the engine mount bushings were considered and the properties of the hydrodynamic oil film at the journal bearings were modeled with “Enhanced Short Bearing Model”. Accelerations at each engine mount were calculated. It is concluded that the natural frequencies of the acceleration show good correlation between the analysis results and the test results. However, regarding the acceleration level at the engine speed ranging between 2000 rpm and 4000 rpm, analysis results are partially higher than test results.