Combined use of equivalent center mass and stiffness factors to better estimate frequencies of mass loaded plates

This paper is concerned with the frequency analysis of vibrating plates car rying multiple masses at various positions. By Virtue of an equivalent cent er method, the frequencies of the plates carrying multiple masses can be pr edicted by using merely the data obtained earlier for the same plate with e ach corresponding mass component. Further accounting the change of the stra in energy into the model, by introducing respective stiffness ratios, enabl es one to obtain a quick and better estimation of the loaded plates with va rious boundary conditions. The proposed model is validated through experime ntation of a rectangular clamped plate carrying concentrated masses. Analyt ical and experimental results for the plate system are compared and discuss ed. It is found that the change in the strain energy should be incorporated in the model, especially for cases of large masses placed on a thin plate, in order to predict well the natural frequency of the amalgamated system f rom those of the component systems. The excellent performance of the propos ed model is due to the fact that the effects of both the different masses a nd their locations on the frequency have been accounted for implicitly in t he respective equivalent center mass and stiffness factors. Although the mo del considered is rather simple, the proposed methodology can be extended t o plates with other geometry and configurations. (C) 2000 Elsevier Science Ltd. All rights reserved.