Local-Global Analysis for Plastic Collapse of Shells

壳体结构的倒塌往往是突然发生的，具有局部性 在性格上，几乎总是与可塑性有关， 预屈曲或后塌陷状态。 的主要目标 研究的目的是建立一个分析模型， 研究这种局部的外壳塌陷。 虽然模型是为了 最初是在旋转壳的背景下开发的，可能的话， 扩展到其他类型的炮弹是在视线中，并将拼写 出去 非线性被假定为被限制到一个可定义的 壳的区域。 在这个区域，一般的四边形 考虑大挠度的退化壳单元， 塑性效应将被用来捕捉本地化的 变形 在其他地方，该行为只是使用 轴对称壳元 连接这些类型的元素， 过渡元素具有“线节点”沿其共同的沿着 边界转化为旋转壳单元和其他地方的点节点。 动态分析将被纳入到跟踪管理单元 这种坍塌总是伴随着塑性。 它 预计这项研究将为我们了解 壳的局部坍塌力学，具有重要价值 在壳体结构的分析与设计技术方面。

The collapse of shell structures often occurs suddenly, is localized in character, and almost always associated with plasticity in the prebuckling or post-collapse state. The major objective of the research is to develop an analytical model which can be used for the study of such localized collapse of shells. Though the model is to be developed initially in the context of rotational shells, possible extensions to other types of shells are in sight and will be spelled out. The nonlinearities are assumed to be restricted to a definable region of the shell. In this region, general quadrilateral degenerate shell elements incorporating large deflection and plasticity effects are to be used to capture the localization of deformation. Elsewhere the behavior is simply described using axisymmetric shell elements. Connecting these types of elements, are the transitional elements which have 'line nodes' along their common boundaries into rotational shell elements and point nodes elsewhere. A dynamic analysis is to be incorporated to trace the snapthrough type of collapse which is invariably accompanied by plasticity. It is anticipated that the research will shed some new light on the mechanics of localized collapse of shells and be of significant value in the technology of analysis and design of shell structures.