NONLINEAR-ANALYSIS OF AXISYMMETRICAL DEFORMATION OF SHALLOW SPHERICAL-SHELLS BY LEAST-SQUARES COLLOCATION METHOD

A nonlinear analysis for deformation and buckling of shallow spherical shells with a central circular opening is presented. The shell is und er a vertical ring load at the opening and/or a uniformly distributed surface load. The method of least squares collocation is used in the a nalysis. Examples for the degenerated case of annular plates and shall ow spherical shells with a central opening under different loading con ditions are presented. The results agree well with existing solutions, and the method used is effective and accurate resulting in steady con vergent solutions according to the numerical examples. While the buckl ing load for clamped shallow spherical shells subjected to uniformly d istributed surface load increases with the increase of the rise-to-thi ckness ratio, the buckling load decreases when the shell is under a un iformly distributed ring load at the central opening.