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In this paper, the natural vibration characteristic of the porous metal cylindrical curved panel under the spring supported boundary conditions is studied. The material of cylindrical curved plate is porous metal, and in thickness direction, three types of porosity distribution are considered. Theoretical formulations for the free vibration of the cylindrical curved panel are established using the first-order shear deformation theory (FSDT) and Hamilton's principle, and a novel dynamics system for porous cylindrical curved panel in physical space is presented. Then, by employing differential quadrature method (DQM), the governing equations of natural vibration in form of partial differential equation and equations describing boundary conditions are discretized into algebraic equations. Unified solution for free vibration of curved panel with arbitrary boundary conditions is obtained. The system's mode shapes and natural frequencies are identified. Moreover, the influence of geometric dimensions, spring stiffness, porosity and types of distribution on the natural vibration of the cylindrical curved panel are studied in detail. The results show that the approach proposed here can efficiently extract analytical expressions of vibration for cylindrical curved plate with arbitrary boundary conditions in physical space • A novel dynamics system for porous cylindrical curved panel in physical space is presented. • The artificial spring technique is employed to the porous cylindrical curved panel. • Unified solution for free vibration of curved panel with arbitrary boundary conditions is proposed by using DQM. • Natural vibration of porous cylindrical curved panel with the two interesting spring supported boundary is studied. [ABSTRACT FROM AUTHOR]

In this paper, the natural vibration of an elastically supported porous truncated joined conical-conical shell (JCCS) is studied. The elastic support is achieved by using artificial spring technology. Four types of the metal foam porous distribution are presented, i.e. the uniform distribution along the radial direction and three other types of the gradient distribution. By applying Hamilton principle and the first order shear deformation theory (FSDT), dynamic equations of motion of the JCCS in the form of partial differential are derived. Considering the elastically supported boundary conditions, displacements continuity conditions and forces continuity conditions at the joining section of the coupling conical shell, partial differential equations used to describe this dynamic system are simplified into a set of algebraic equations by utilizing the generalized differential quadrature method (GDQM), in which the trigonometric function is used in the circumferential direction, while in meridian direction the DQ is applied. To obtain the natural vibration characteristic of the JCCS, the eigenvalue solving technology is utilized. The validation and convergence of the theoretical formulation are confirmed by comparison studies. Influences of boundary conditions, the spring stiffness, the geometric and material parameters on natural frequencies and mode shapes of the JCCS with two particular elastic boundary conditions are studied in detail. [ABSTRACT FROM AUTHOR]