基于构形易损性理论的单层网壳结构静力稳定性研究

发布时间：2018-01-11 16:27

本文关键词：基于构形易损性理论的单层网壳结构静力稳定性研究　出处：《工程力学》2017年01期 　论文类型：期刊论文

【摘要】：经典构形易损性理论基于结构初始构形度,无法考虑荷载、约束等外在因素,但网壳结构的稳定性却与上述因素密切相关。在经典构形度的基础上,该文创新地引入几何刚度矩阵,提出了可以考虑荷载条件、几何非线性及约束的节点构形度计算方法。在此基础上,分析引入几何刚度矩阵前后节点构形度的变化梯度,识别了球壳结构的最不利稳定荷载模式并揭示了失稳机理。最不利稳定荷载模式具有构形度变化梯度显著、稳定承载力最低的特征。对于球壳结构,顶点集中荷载为最不利荷载模式。点失稳、局部失稳以及整体失稳模态均与构形度变化梯度相联系。当受荷点及其周边节点构形度显著退化时,结构发生点失稳破坏,对应顶点集中荷载模式;当部分节点区域构形度明显退化时,结构呈现局部失稳的模态,对应半跨均布荷载模式;当所有节点构形度发生同等程度的退化时,结构发生整体失稳,对应满跨均布荷载模式。
[Abstract]:The classical structure vulnerability theory is based on the initial configuration of the structure, and can not consider external factors such as load and constraint, but the stability of reticulated shell structure is closely related to the above factors. In this paper, the geometric stiffness matrix is introduced, and the calculation method of node configuration is proposed, which can take into account the load condition, geometric nonlinearity and constraint. The change gradient of node configuration before and after introducing geometric stiffness matrix is analyzed and the most unfavorable stable load mode of spherical shell structure is identified and the mechanism of instability is revealed. The characteristics of the lowest stability bearing capacity. For the spherical shell structure, the peak concentrated load is the most unfavorable load mode, and the point instability. The local instability and global instability are all related to the gradient of configuration change. When the configuration of the loaded point and its surrounding nodes degenerates significantly, the structure is damaged by point instability, corresponding to the vertex concentrated load mode. When the configuration degree of part of the joint region degenerates obviously, the structure presents the mode of local instability, corresponding to the half span uniform load mode. When all the joints degenerate to the same degree, the whole structure is unstable, corresponding to the full span uniform load mode.
【作者单位】：东南大学混凝土与预应力混凝土结构教育部重点实验室;
【基金】：国家杰出青年科学基金项目(51125031)
【分类号】：TU399
【正文快照】： 单层网壳结构设计中要考虑的一个重要问题是结构稳定性。现阶段的研究成果和工程经验均表明,网壳结构稳定性已经超越了强度、刚度问题,成为网壳结构设计中的主要因素。单层网壳的极限承载力也往往是由稳定承载力决定。因此,网壳稳定性能的研究对于提高结构安全储备、实现更为

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