轴压柱形壳非线性屈曲试验与理论研究

Experimental and theoretical study on nonlinear bucklingof axially compressed cylindrical shells

本文研究了轴压不锈钢柱形壳的非线性屈曲行为。通过轴向压缩试验,获得柱壳的载荷位移曲线、失稳载荷、最终失稳模式;在此基础上,采用弧长法对试验壳体进行非线性屈曲计算,分析平衡曲线、临界载荷、临界屈曲和后屈曲模式等非线性屈曲行为,并与试验结果作对比研究。结果表明:在柱形壳受轴压而发生弹塑性屈曲时,端部长度缺陷会在轴压初期降低柱形壳的承载力从而影响临界屈曲载荷,且高度越小时,柱形壳越容易在两端发生形变。但是总体来看,发生塑性屈曲时,端部长度缺陷对临界载荷影响很小。

The nonlinear buckling behaviors of stainless steel cylindrical shells under axially compressed loadings are studied.The axial compression tests are carried out to obtain the load-displacement curves,the buckling loads and the post buckling modes of such shells.On this basis,nonlinear buckling behaviors such as the equilibrium curves,critical loads,critical buckling and post-buckling modes are analyzed.The results of analysis are well consistent with experimental data.The results show that when the axially compressed cy⁃lindrical shells buckle in an elastic-plastic range,the end length imperfection will reduce the bearing capaci⁃ty of the cylindrical shells at the initial stage of axial compression and affect the critical buckling load.The smaller the height is,the easier it will be for the cylindrical shells to deform at both ends.However,in gener⁃al,when plastic buckling occurs,such imperfection has a slight effect on the critical load.