Direct Vibration Response Estimation of a Modified Structure without Using Exciting Force

(Estimation Accuracy when Exciting Force and Displacement Act on a Structure Simultaneously)

Abstract

The proposed method presents an approach to estimate the responses of vibration without using exciting force and displacement excitations. It is useful for the practical development in industries, in the case of excitation force and excitation displacements act at the same time, even if Guyan's static reduction method is applied for the beam model, numbers of the measuring points and used modes are reduced. The responses of vibration are usually calculated by modal parameters and exciting forces. However, force estimations spend the long time and manpower. The proposed method has a merit to be able to calculate the responses after the modification of a structure by (a) prototype vibrations of designated points on running conditions, (b) modal parameters of the structure before modification and (c) stiffness and mass matrices differences of modification area between before and after modification. These data are usually available during noise and vibration development tests so that the proposed method does not need additional man power.