Micromechanical damping analysis of composite materials using linear viscoelasticity vs the strain energy approach

The phenomenological strain energy approach for predicting composite damping properties is widely used because of its simplicity. The composite dissipated energy is approximated as the volume average of the local (constituent) loss factor times the local strain energy. Thus, any micromechanics method (e.g., finite element or the high-fidelity generalized method of cells used herein) that can predict the local fields (and thus the strain energy) within a composite can be used to approximate the effective damping properties. In this paper, two more physics-based approaches, the correspondence principle and explicit viscoelastic modeling, are implemented within the two-scale high-fidelity generalized method of cells micromechanics theory and compared with the widely-used strain energy approach. It is shown that all three approaches provide quite similar predictions for the effective damping properties of unidirectional composites. Finally, the presented two-scale micromechanics theory is applied to predict the effective anisotropic damping properties of 2D and 3D woven composites.