STRUCTURAL AND KINEMATIC VIBRATION ON INTERNAL COMBUSTION ENGINE - PART I

Computational methods to predict the vibration of an internal combustion engine have become more important as demands for matching the lighter weight with low vibration levels and for reducing the development period have been increasing. The former studies of engine vibration are categorized into two groups. One deals with structural vibration (elastic vibration) in relatively higher frequencies. The other deals with kinematic vibration (rigid body motion) in low frequencies. Recently, it is becoming more important to analyze structural and kinematic coupled vibration in middle range frequencies. In this study, we developed an engine vibration analysis system for a computer aided design software, which can comprehensively analyze structural and kinematic coupled vibration in a wide range. A new formulation using a local observer frame and eigenmodes was proposed to efficiently calculate the structural and kinematic coupled vibration of the moving elastic body. In addition, some types of force elements were developed to express the transmitting force from a body to another body or the boundary conditions. The developed program was applied to a real engine model and verified by experiment under running conditions