Composite Structure Analysis of a Hollow Cantilever Beam Filled with Electro-Rheological Fluid

Unwanted vibrations within structures can become an ever increasing problem as structural components are made lighter with the use of advanced materials and tighter design tolerances. Increased operating bandwidth further compounds the problem resulting in the build up of unwanted vibrations within optimally designed structures. The alteration of the spectral signature of a structural component will enable the aforementioned design criteria to be satisfied. The use of a hollow structural component filled with Electro-Rheological fluid will enable the spectral signature of the component to be altered electrically. Experimental data obtained for a hollow cantilever beam filled with Electro-Rheological fluid is presented in this paper. Analysis of the data is carried out to determine heuristic values for the beams effective stiffness 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 oscillating composite structure cantilever beam. Differences between the predicted and the heuristic data is then examined with regard to a hypothesis based on the behaviour of the induced ER fluid's microscopic structure.