Influence of the support conditions in the modal parameters of a cantilever beam

Abstract

In modal analysis, previously to the modal testing, it is very common to assembly a finite element model, in order to know the frequency range of interest and the mode shapes of a structure. This information is very helpful for planning and developing the modal testing. On the other hand, the proper modeling of the support conditions and the joints are the main difficulties in model assembly and model updating. For these reasons, the results obtained in the modal tests are, sometimes, unexpected. In this paper it is studied the effect of the support conditions in the modal parameters of a steel cantilever beam with different kinds of foundations. Moreover, a technique based on the analysis of the singular value decomposition of the responses, using different number of sensors, is proposed and validated by experimental test carried out on a steel cantilever beam tested in the lab. © The Society for Experimental Mechanics, Inc. 2013.