Component Modal Tests with Additional Mass and Stiffness

摘要

This paper describes amethod to predict the dynamic characteristics of large structures, such as satellite antennasnand solar paddles. It has become increasingly difficult to performmodal tests for large space structures, because theynare not strong enough to withstand the force of gravity. Component modal tests are effective at identifying thendynamic characteristics of structures consisting of several components. In this method, the effect of untestedncomponents are considered as additional mass and stiffness attached to a tested component. Additional mass andnstiffness, attached to an arbitrary coordinate, are found by reducing mass and stiffness matrices of untestedncomponents. Modal tests for different tested components give identical frequencies, so these frequencies arenconsidered the frequencies of structures. The feature of the proposedmethod is to obtain the dynamic characteristicsnof large structureswith componentmodal tests and to need no componentmode synthesis.Numerical examples shownthat the proposed method has the potential to predict the dynamic characteristics of large structures by componentnmodal tests.