加肋球壳稳定性样条元分析

本文采用样条能量法分析旋转壳体的稳定性。文中利用样条函数的数学性质导出了步长积分矩阵,并将等步长样条元推广为变步长;处理了双向积分变量的耦连性;分析了加肋球壳的整体失稳和局部失稳。

Stability Analysis for Spheric Shell with Stiffeners Using Spline Element

The stability of spheric shells with stiffeners is analyzed with the spline-energy method. The shell is dissected in belt elements along the longitudinal direction. Cubic B-spline is used to form displacement functions. Trigonometric series expansion is carried out along the latitudinal direction of the shell. It is difficult to integrate over the entire spheric shell as there exists coupling between bidirectional variables in energy integral matrix. However, the integral matrix for each step is derived by the author by making use of the mathematical property of the spline function and the dif-ficulty is overcome. The constant step spline element method has been extended to variable step ones and then it is suitable for an irregular structure; The critical pressure is computed for overall and local buckling of spheric shell with simple shell and with various stiffeners under uniformly distributed loadings. The influence of stiffeners on the stability of spheric shell is discussed.