On the dynamic characterization of joints using uncoupling techniques

Abstract

An incorrect theoretical model for a joint may provide a bad (or not so good) representation of the behavior of the structure and a posteriori corrections and/or updating techniques may not be able to give a good enough cure for the problem. Joints are typical structural elements that most of the times can only be adequately characterized from experimental results. However, testing a joint to determine its properties is also a problem, mainly due to its dimensions and working conditions, as when separated from the structure it may be difficult to reproduce accurately the way it is performing in reality. The most correct way to characterize the joint seems to be by uncoupling from the whole structure the substructures connected through the joint. This process may have its own difficulties and in this paper an alternative technique is proposed to help solving the problem, where there is no need to measure FRFs at the joint coordinates, which is usually difficult to do. Some numerical examples are presented to illustrate the procedure.