摘要
Inverse structural modifications have been studied in theory but rarely implemented in practice. In this paper, the inverse structural modification theory based on receptances is further developed. The receptances of a modified structure are expressed in terms of the receptances of the original structure and the modifications to be made, which allows measured receptances to be used instead of system matrices or a modal model (and thus a theoretical model of the structure is not needed). The method proposed in this paper can be applied to assignments of several different kinds of dynamical properties such as natural frequencies, antiresonant frequencies and receptances, and to make pole-zero cancellation. To address the lack of experimental validation to inverse structural modification problems in published papers, a geared rotor-bearing system is manufactured and tested to validate the method and provide experimental insights. Experimental results show that more than one natural frequency or antiresonant frequency can be assigned within acceptable accuracy and the sensitivity of modifications is crucial for the solutions of modifications cast as an optimization problem. An additional application for determining the optimal locations for given modifications to achieve the highest first natural frequency is also presented. The experimental results obtained prove the effectiveness and the ease of use of this proposed method. This work should help make inverse structural modification a popular means of passive vibration control to improve the dynamical behaviour of real structures.