Analysis of Forced Vibration with Reduced Impedance Method : Part l, Introduction of Analytical Procedure

Abstract

Forced vibrations of mechanical structures are analyzed by the reduced impedance method the authors proposed. A structure is divided into some components, and the mechanical impedances of these components are calculated by the finite element method. These impedances are reduced and combined to get a united equation of the forced vibration. The forced vibrations of a plate, a box specimen and an actual cylinder block are analyzed by this method, changing the damping coefficient and the number of the finite elements of the components. On the other hand, the steady state vibration is measured under a harmonic exciting force, and the mechanical impedance is determined form the measured wave of the force and the acceleration. The calculated results are compared with the experimental ones in order to check the accuracy of the theoretical analysis, and both results agree well with each other.