Dynamic Response of Sandwich Panels with Flexible Cores and Elastic Foundation Subjected to Low-Velocity Impact

In this paper, for first time dynamic response of composite sandwich panel with a flexible core on elastic foundation under low-velocity impact load is studied. The governing equations of sandwich panel are obtained using the Hamilton principle and energy method. Free vibration analysis of panel is based on the improved higher-order sandwich panel theory (IHSAPT) by considering elastic foundation effects in equations. The formulation uses the first shear deformation theory (FSDT) for face sheets and Frostig’s second model for core. The equations system is solved for plate on elastic foundation using two parameters Pasternak model. For dynamic analysis of composite sandwich panel under low-velocity impact load, the sandwich panel is modeled as a two-degrees-of-freedom dynamic system with equivalent masses and springs using linearized Hertz contact law from Choi method. In this model for impact solution, fundamental natural frequency has been used directly for calculation of the equivalent stiffness of panel. Effect of variation of various vertical and transverse shear modulus of elastic foundation on natural frequencies of free vibration, contact force history and transverse displacement of panel in low-velocity impact analysis is discussed and is compared with the available results in literature.