Study of Damping Characteristics in Fiber Reinforced Composite Beams

Vibration has adverse effects in many applications ranging from small components used in electronics to huge building constructions and bridges. In mechanical systems, it affects machine tool structure as well as decreases accuracy, surface finish and increases noise. Hence, it becomes necessary to avoid vibrations by increasing damping of the structures. Damping is resistance to vibrations. One such way of increasing damping of the structure is by using composites. Composites are nowadays replacing conventional materials owing to their better damping and mechanical properties. For replacement of conventional materials with composites considering vibrational parameters, it is necessary to study damping properties of composites. The current research deals with estimating the damping properties of composites. Glass fiber reinforced epoxy (GFE) and Glass fiber reinforced polyester (GFP) were initially used as raw materials to study damping in composites. It was found that GFE possesses more damping compared to GFP and hence used for further study. Processing of GFE was done using hand-lay technique. Various design parameters such as numbers of glass fiber layers and orientations of fibers were varied while manufacturing GFE composites. Further, experimental parameters such as loading frequency and cantilever length were varied during damping tests. It was found that as the number of layers increases damping of GFE increases. Also +45-(-45) fiber orientation gives better damping compared to 0-90 orientation