مشخصات پژوهش

In the present paper, for the first time, the dynamic loading effect on transient bending and stress distributions of aircraft nanocomposite sandwich panels including curvilinear fibers are presented and explained. Face sheets of the panel contain curvilinear fibers with an orientation angle varies linearly with respect to the horizontal coordinate. The core layer is made of polymer matrix reinforced by graphene platelets (GPLs) with uniform and random orientation distribution. 3-D elasticity theory is used to formulate the transient problem of the panel. The model of the panel is so general to include different time-dependent loads, especially explosive ones. A threedimensional layerwise-differential quadrature method (LW-DQM) together with a non-uniform rational Bspline-based multi-step time integration scheme is employed to investigate the transient responses of the sandwich panel with variable stiffness composite laminated face sheets (VSCL-FS) and graphene platelets reinforced porous core (GPLR-PC) under dynamic loading. The convergence behavior of the method is examined numerically and to assure its accuracy, the results in the limit cases are compared with those available in the literature. Finally, through the parametric studies, the effects of core porosity distribution and amounts, GPLs weight fraction and boundary conditions on the transient responses of the sandwich panel with VSCL-FS and GPLR-PC subjected to explosive blast loading are investigated. The results show that the addition of GPLs to the core layer decreases the transverse displacement but increases the peak values of the stress components. Also, the core porosity increases the transverse displacement and the stress components. However, it has not significant effect on the period of oscillation of the field variables under explosive blast loading. On the other hand, the curvature of the fibers does not considerable effect on the plate response and on the period of oscillation of the field var