Qom University of Technology
Abstract: (74 Views)
This paper presents a novel investigation into the free vibration of porous folded plates using the differential transformation method (DTM). The porosity is functionally graded (FG) along the thickness of the plate, resulting in material properties that vary with the z-coordinate. The motion equations for each plate segment are derived based on classical plate theory (CPT), with simply-supported boundary conditions applied at the front edges, allowing the transformation of partial differential equations into ordinary differential equations. The differential transformation method is then employed to discretize the motion equations in the x-direction. By applying boundary conditions at the remaining edges and ensuring continuity at the joints, the eigenvalue problem is formulated, leading to the calculation of natural frequencies and mode shapes of the folded plate. The mathematical model is validated through comparisons with finite element method (FEM) results and existing literature. Results indicate that Type C porosity distributions exhibit the highest stiffness and resonant frequency compared to other porosity types. While frequency behavior is consistent across mode numbers regardless of porosity distribution and plate length, the impact of the porosity parameter on the frequency of Type C plates is demonstrably less significant than on other porosity types.