magneto-electro vibration analysis of a moderately thick double-curved sandwich panel with porous core and gplrc using fsdt

In the present study, the magneto-electro vibration analysis of a moderately thick double-curved sandwich panel with porous core and graphene platelets reinforced composite (gplrc) based on the nonlocal strain gradient theory (nsgt) is investigated. the displacement field of a moderately thick double-curved sandwich panel is considered as the first-order shear deformation theory (fsdt). the equations of motion are derived using hamilton’s principle and these equations are solved by navier’s method. the effect of various parameters, including magnetic and electric fields, aspect ratio, core-to-face thickness ratio, volume fraction of gpls, different porosity distributions, various gpls distributions, and curvature radius on the dimensionless natural frequencies of a moderately thick doubly-curved sandwich panel is examined. in this research, the sandwich structures become consist of two thin face sheets with high strength and a thick, soft, and flexible core with low density, because the scientists follow to enhance the strength to weight in the sandwich structures that these structures are used in various industries. in this article, the doubly-curved sandwich panel includes cylindrical, spherical, and elliptical shapes. the main finding of this research is that the dimensionless natural frequency reaches its maximum value at hc/hf = 6.