COMPOSITE STRUCTURE-ANALYSIS OF A HOLLOW CANTILEVER BEAM FILLED WITH ELECTRORHEOLOGICAL FLUID

Unwanted vibrations within structures can become an ever increasing pr oblem as structural components are made lighter with the use of advanc ed materials and tighter design tolerances. Increased operating bandwi dth further compounds the problem resulting in the build up of unwante d vibrations within optimally designed structures. The alteration of t he spectral signature of a structural component will enable the aforem entioned design criteria to be satisfied. The use of a hollow structur al component filled with Electro-Rheological fluid will enable the spe ctral signature of the component to be altered electrically. Experimen tal data obtained for a hollow cantilever beam filled with Electro-Rhe ological fluid is presented in this paper. Analysis of the data is car ried out to determine heuristic values for the beams effective stiffne ss and damping coefficient. The effects of applying an electric field to the ER fluid are outlined from the results obtained. Comparison of the results is then made with those predicted by a model of an oscilla ting composite structure cantilever beam. Differences between the pred icted and the heuristic data is then examined with regard to a hypothe sis based on the behaviour of the induced ER fluid's microscopic struc ture.