The geometric nonlinear response of spherical shells made of sandwich functionally graded material (SFGM) under uniform external pressure incorporating the effects of transverse shear deformations is considered. The equilibrium and compatibility nonlinear differential equations can be solved by using the modified interaction method. All of the equations are developed based on the first-order shear deformation theory (FSDT). In the present study, the geometric nonlinear problem has been solved for special boundary conditions including movable and fixed clamped supports in the meridional direction. A closed-form nonlinear load-deflection relationship is developed for SFGM shell which expresses the equilibrium path of the shell.

考虑了由夹层功能梯度材料（SFGM）制成的球壳在均匀外部压力下的几何非线性响应，并考虑了横向剪切变形的影响。平衡和相容非线性微分方程可以通过使用改进的相互作用方法来求解。所有方程都是基于一阶剪切变形理论（FSDT）开发的。在本研究中，已经解决了特殊的边界条件，包括在子午方向上的可移动和固定夹紧支撑的几何非线性问题。建立了SFGM壳体的闭合形式非线性载荷-挠度关系，表示壳体的平衡路径。