Modeling the response of composite panels by a dynamic stiffness approach

A dynamic stiffness approach for the prediction of the vibratory response of thick laminates and sandwich panels is hereby proposed. Initially, the wave dispersion characteristics of a two dimensional periodic medium are numerically predicted using a Wave Finite Element Method (WFEM). The effects of layer coupling on wave propagation within the laminate are therefore captured through a full three dimensional Finite Element (FE) modeling for a wide frequency range. The computed dispersion characteristics are used in order to update classical plate theories and calculate a dynamic stiffness matrix for the modeled laminate. The resulting updated Equivalent Single Layer (ESL) modeling proves to be time efficient and accurate for a wide frequency range. An experimental validation of the presented approach is also conducted. The response of a honeycomb orthotropic sandwich panel is measured and is successfully compared to the prediction of the ESL model. The WFEM computed wavenumbers are also validated by experimental measurements. The accuracy and the computational efficiency of the WFEM homogenization are discussed and compared to the ones of modern refined shell theories. The approach proves to be computationally efficient, numerically simple and accurate in a broadband frequency range.