Path Contribution Analysis of Vibration Transfer Path Systems

Abstract

To analyze the vibration characteristics of mechanical systems from the aspect of vibration transfer, two types of models for vibration transfer path systems were designed, which comprised three subsystems: excitation sources, transfer paths, and receivers. One type of model represented that the systems only sustained unidirectional force excitation, where the transfer paths remained free from the influence of mass parameters. The other type indicated that the systems were subjected to simultaneous excitations of forces and moments, with transfer paths without mass parameter. Because the transfer characteristics of vibration paths directly determine the output response behaviours of the systems, the analysis of path contributions to the vibration responses of system receivers is important in systemic vibration and noise reduction. In order to evaluate the path contributions quantitatively, the concepts of path transfer ratio (TR) and path insertion loss (IL) were introduced and the convenient formulae were derived based on the path transfer force analysis and the path disconnected method in this work. Thereby the measurement of path contributions to the receiver vibration responses within the frequency domain can be accomplished. Through numerical examples, the ideal calculation results were obtained. These conclusions further indicate that the path TR and path IL can be applied as evaluation indicators of path contributions for the vibration transfer path systems.