Strength Deterioration of Thin-walled Structures due to Localization of Plastic Buckling Patterns under Cyclic Loading

利用去年编制的计算机程序，研究了本构模型对薄壁结构局部化行为的影响。此外，通过分析和实验研究了厚圆柱壳的轴对称屈曲模式的循环局部化，特别是它对变形能力的影响。所得结果概括如下：1)本构模型对受压板局部化行为的影响。与双面本构模型相比，双线性本构模型的压板在较小的面内位移下表现出局部化现象。采用双表面本构模型的板的初始位移对循环局部化行为有一定的影响。2)局部化行为对厚圆柱壳变形能力降低的影响。作者提出的分析方法较好地模拟了实验所显示的厚壁圆柱壳的局部化行为。圆柱壳的径厚比(R/t)和长径比(L/R)越大，发生局部化时的载荷降越大。在循环荷载作用下，本构模型对土体的局部化行为有显著影响。

The effect of constitutive models on the localization behavior of thin-walled structures was investigated by making use of the computer program developed last year. In addition, the cyclic localization of axi-symmetric buckling patterns of thick cylindrical shells was investigated by analysis and experiment with special emphasis on its effect on the deformation capacity. The results so obtained are summarized in the following.1)Effect of constitutive models on the localization behavior of compression platesa. The compression plates with the bi-linear constitutive model exhibit localization phenomena under smaller in-plane displacements, compared to those with the two-surface constitutive model.b. Initial displacements of the plates with the two-surface constitutive model have some effect on the cyclic localization behavior.2)Effect of localization behavior on the reduction of deformation capacity of thick cylindrical shellsa. The analysis method proposed by authors well simulate the localization behavior of thick cylindrical shells shown by the experiment.b. The cylindrical shells with larger radius-thickness ratio (R/t) and length-radius ratio (L/R) exhibit a larger load drop when the localization occurs.c. The effect of the constitutive models is significant in the localization behavior under cyclic loading.