Vibration and buckling analysis of laminated sandwich conical shellsusing higher order shear deformation theory and differential quadraturemethod

Vibration and buckling analysis of laminated sandwich truncated conical shellswith compressible or incompressible core are presented in this work consideringcurvature effects. The formulation uses the quadratic and cubic functions fortransverse and in-plane displacements of the core and the first-order sheardeformation theory for the face sheets. The motion equations of each individuallayer are derived according to the principle of minimum total potential energyconsidering the continuity of the displacements and the internal stress fieldsat the interfaces. Differential quadrature method is applied in order to obtainthe frequency and buckling load of the sandwich structure. The effects ofdifferent parameters such as core to face sheet stiffness ratio, number oflayers of the face sheets, boundary condition, geometrical parameters of thecore and the face sheets, semi vertex angle of the cone, trapezoidal shape, andin-plane stresses of the core are examined on the vibration and bucklingresponse of sandwich truncated conical shells. Comparison of the present resultswith those reported in the literature confirms the accuracy of the proposedtheory. Numerical results indicate that the effects of in-plane stresses of thecore significantly affect the frequency with increasing the core to face sheetstiffness ratio.