پرویز ملک زاده

As a first attempt, the dynamic responses of sandwich truncated conical shells with graphene platelets reinforced composite (GPLRC) face sheets, porous core and circumferential stiffeners under asymmetric internal ring-shaped moving load are analyzed. The face sheets and porous core are reinforced by uniformly distributed and randomly oriented graphene platelets (GPLs). The spatially discretized equations of motion subjected to different boundary conditions are derived based on the first-order shear deformation theory (FSDT) using the Chebyshev–Ritz method. The admissible functions of the field variables are constructed using the trigonometric functions in the circumferential direction and the one-dimensional Chebyshev polynomials in conjunction with the suitable boundary functions in the meridional direction. The Newmark’s time integration scheme is employed to solve the resulting ordinary differential equations of motion. The robustness and accuracy of the method are demonstrated through the different examples. After that, the influences of core porosity, face sheets, GPLs parameters, shell geometric parameters, boundary conditions, and the arrangement, number and size of stiffeners on the results are explored. The results show that porosity, face sheets, the location, size and number of stiffeners play important roles on the dynamical response of the shells under investigation. Also, it is found that the critical load velocity decreases by increasing the porosity coefficients and increases by increasing the number of ring-stiffeners.