Dynamic stability characteristics of functionally graded materials shallow spherical shells

Here, the dynamic stability behavior of a clamped functionally graded materials spherical shell structural element subjected to external pressure load is studied. The material properties are graded in the thickness direction according to the power-law distribution in terms of volume fractions of the constituents of the material. The effective material properties are evaluated using a homogenization method. The structural model is based on shear deformation theory and geometric non-linearity is considered in the formulation using von Karman's assumptions. The governing equations obtained are solved employing the Newmark's integration technique coupled with a modified Newton-Raphson iteration scheme. The load corresponding to a sudden jump in the maximum average displacement in the time history of the shell structure is taken as the dynamic buckling pressure. The present model is validated against the available isotropic cases. A detailed numerical study is carried out to bring out the effects of power-law index of functional graded material on the axisymmetric dynamic stability characteristics of shallow spherical shells. (c) 2006 Elsevier Ltd. All rights reserved.