An efficient finite element method for computing modal damping of laminated composites: Theory and experiment

This paper presents an efficient finite element method (FEM) for computing the modal damping of laminated composites using the general purpose finite element software. The method is based on an extended elastic-viscoelastic correspondence principle, which accounts for the frequency dependence of viscoelastic complex stiffness matrices. The implementation of the proposed model is described as a UMAT subroutine for ABAQUS/Standard. The experimentally determined material complex modulus values for the carbon/epoxy laminated composites combined with the results of cantilever percussion free-decay testing are used as the input parameters for the model. Subsequently, the analyses of modal damping and frequency response for laminated composites are implemented by using the complex eigenvalue method. The computed results from this model are in good agreement with the test data. Thus, the proposed numerical method is quite efficient and accurate, and capable of providing an effective way to determine the modal damping of anisotropic materials by using ABAQUS code.