Micromechanical Modeling of Damping in Discontinuous Fiber Composites Using a Strain Energy/Finite Element Approach

The purpose of this paper is to describe the development and demonstrate the application of an efficient method for finite element modeling of damping and stiffness of discontinuous fiber reinforced composites. Dynamic stiffness and damping are defined in terms of the complex modulus, and composite damping is estimated by means of a strain energy method. This technique has the capability of predicting fiber interaction and fiber interface effects on composite damping. The resulting data from the analytical approaches, including the finite element method (FEM) and a “mechanics of materials” analysis, were compared with previous experimental results. These results showed that fiber interaction does affect the damping of discontinuous fiber composites, and that damping can be improved by increasing the fiber end gap size or by decreasing the fiber aspect ratio. It is also shown that the finite element implementation of the strain energy approach is a powerful tool for predicting the damping in composites.