ELASTO THERMODYNAMIC DAMPING IN METAL-MATRIX COMPOSITES WITH SPHERICAL REINFORCEMENT

Abstract

Metal-matrix composites are being widely used in space structures. Any unwanted vibration severely affects the performance of these structures and any external means of damping out these unwanted vibrations is difficult to provide. Elasto Thermodynamic Damping (ETD) is a source of damping present in all thermoelastic materials. It is due to the flow of thermal currents in the material and hence the strength and stiffness' properties remain unaffected. The magnitude of ETD is normally very small in homogeneous materials. But for heterogeneous material combinations, such as composites, this effect may be significant. In the present work, the concept of ETD has been introduced and the relevant literature has been reviewed. The review indicates that, there is a need for the analysis of ETD in particulate composites with a more realistic model of a composite. With this in view, the generalized self- consistent approach has been used to model metal-matrix composites, with spherical reinforcement. The problem formulation and the solution scheme for evaluating ETD have been presented. The effects of excitation frequency and thermoelastic properties of the constituents of the composite have been studied. It is concluded that the present work will be helpful in tailor-making advanced composites with better damping behaviour