Low-velocity impact response of FG-GRC laminated beams resting on visco-elastic foundations

This paper presents an investigation on the low-velocity impact response of a functionally graded graphene reinforced composite (FG-GRC) laminated beam subjected to a transverse impact load. The beam is assumed to rest on visco-Pasternak foundations in thermal environments. Each layer of the laminated beam has the same thickness, but the volume fraction of graphene reinforcement for the layers may be different and vary along the thickness direction in a piece-wise functionally graded pattern. The temperature dependent material properties of graphene reinforced composites (GRCs) are estimated by an extended Halpin-Tsai model, where the graphene efficiency parameters are introduced and determined from the results of molecular dynamics (MD) simulations. The impactor that applies the impact load to the beam may act at any position of the beam for which the central impact is treated as a special case. The contact process follows a modified Hertz model. The linear motion equations of the FG-GRC laminated beam are established based on a higher-order shear deformation beam theory when the impacted position is arbitrary, whereas the nonlinear motion equations are obtained only for the central impact case. The motion equations of the beam and the dynamic equation of the impactor are then solved simultaneously by the Runge-Kutta approach. The numerical results illustrate the influences of functionally graded graphene distribution, foundation stiffness, temperature variation and different impactor velocities on the central deflection of the FG-GRC laminated beam as well as the contact force between the beam and the impactor.