复合有限条法研究水压作用下加肋柱壳的后屈曲

THE POST-BUCKLING ANALYSIS OF RING-STIFFENED SHELLS UNDER HYDROSTATIC PRESSURE USING COMPOUND STRIP METHOD

为了研究水压作用下的加肋柱壳的后屈曲状况，并且能考虑到肋骨的实际截面形状和分布情况，本文将复合有限条方法应用于环加肋圆柱壳的后屈曲分析。在对后屈曲路径的跟踪过程中，使用了正交弧长法。算例表明，复合有限条方法同纯粹的有限元方法相比在速度上能提高10倍以上，并且方程阶数与壳体尺寸无关，是一种分析加肋板壳结构的理想方法；实际应用的加肋圆柱壳在水压下的后屈曲路径一般来说不存在分叉点，在后屈曲阶段，随着变形的增加常常要求压力有所增加。

In order to find the post-buckling path for ring-stiffened shells under hydrostatic pressure and consider the practical shapes of ring sections, the Compound Strip Method (CSM) is applied to the post-buckling analysis of ring-stiffened cylindrical shells. The improved arc- length orthogonality method is used to track the nonlinear load-displacement path. Numerical examples are provided to demonstrate the CSM. It is shown that the CSM is very computationally efficient in comparison with the finite element method and its total number of degrees of freedom is independent of the dimensions of a shell. It is also found that generally there is no bifurcation point in the post-buckling path for practical ring-stiffened shells under hydrostatic pressure. The pressure is shown to inorease with the displacement. It is concluded that the CSM is an ideal method for analysis of stiffened plate and shell structures.