组合梁平面钢框架抗连续倒塌性能研究

发布时间：2018-06-02 19:15

本文选题：连续性倒塌 + 组合节点　；参考：《哈尔滨工业大学》2014年博士论文

【摘要】：建筑结构一旦发生连续性倒塌，必将造成严重的人员伤亡和巨大的经济损失。因此，结构的抗连续倒塌性能已引起学者和工程界的广泛重视。当结构中的竖向承重构件发生破坏，结构将通过由节点和梁组成的“悬索作用”来承担竖向荷载。在抗倒塌设计中采用承载力高、变形能力好的节点连接，可以充分的发挥悬索作用，保证结构将上部荷载充分并平稳的传递给周边构件。在正常使用荷载作用下，节点承受负弯矩的作用，而当柱失效后，“悬索作用”将在梁中产生拉结力，失效柱上方节点将承受正弯矩和拉力的共同作用，而相邻节点将承受负弯矩与拉力的共同作用。因此，结构体系中的节点性能的研究和设计将是结构抗连续倒塌设计中的关键指标之一。现有结构体系的连续倒塌性能研究多侧重于钢框架和钢筋混凝土框架，对组合梁钢框架的研究则较少。而对于抗连续倒塌体系中节点性能研究则通常采用简化的边界条件，针对组合节点在弯矩和拉力共同作用下的性能也关注较少。为此，本文对组合梁平面钢框架的连续倒塌性能和组合节点的受力性能进行了较为系统的试验研究和理论分析，具体包括以下四部分内容： (1)完成了2榀四跨单层组合梁平面钢框架的抗连续倒塌性能试验研究，考察了焊接刚性组合节点和平齐式端板连接半刚性组合节点对结构体系抗连续倒塌性能的影响。实测了失效柱柱顶荷载、位移以及框架水平位移，获得了框架梁梁端和跨中应变的分布与发展规律，得到了受荷过程中梁中拉力和弯矩的传递过程和规律，比较了梁柱连接方式对组合梁平面钢框架抗连续倒塌性能的影响。 (2)完成了12个钢-混凝土组合节点的试验，考虑了刚性组合节点和平齐式端板半刚性组合节点在纯弯、拉弯和受拉三种工况下的受力机理。实测了组合节点的弯矩-拉力曲线、弯矩-转角曲线和拉力-位移曲线，获得了受荷全过程中梁端的应变分布、发展以及试件的变形特征。基于试验结果和已有的理论分析，提出了组合节点拉弯受力状态的承载力设计方法，并分析了组合节点在抗倒塌过程中不同受力阶段的工作机理。 (3)采用ABAQUS建立了刚性连接和半刚性连接的组合梁平面钢框架有限元分析模型，在半刚性连接框架中采用混合单元建模，考虑螺栓断裂后能更精确模拟平齐式端板连接半刚性组合节点在结构体系中的受力性能。探讨了钢梁截面高度、混凝土板厚度、配筋率、节点连接刚度等参数对关键柱破坏后框架抗连续倒塌性能的影响。基于理论分析和试验研究，提出了组合梁平面钢框架简化分析模型及压拱效应模型，并推导了竖向荷载-位移计算方法。 (4)建立了三层和九层组合梁平面钢框架有限元模型，，对其进行了动力拆柱分析，研究不同层高、不同位置的关键柱破坏后相应节点和结构体系的动力响应和受力机理，确定影响范围及连接性能对结构抗连续倒塌性能的影响规律。通过分析最终提出可用于多层框架结构抗连续倒塌性能分析的简化模型。
[Abstract]:Once the building structure collapses continuously, it will cause serious casualties and huge economic losses. Therefore, the anti collapse performance of the structure has attracted the attention of the scholars and the engineering community. When the vertical bearing member of the structure is destroyed, the structure will bear the vertical charge through the "suspension action" of the joints and beams. In the anti collapse design, the joints with high bearing capacity and good deformability can fully play the role of suspension cable to ensure that the structure transfers the upper load fully and smoothly to the surrounding components. Under normal load, the node bears the role of negative bending, and the "suspension action" will produce a pull knot in the beam after the failure of the column. Force, the joint above the failure column will bear the joint action of the positive bending moment and tensile force, and the adjacent nodes will bear the joint action of the negative bending moment and tension. Therefore, the research and design of the node performance in the structural system will be one of the key indicators of the structural anti collapse design.
The research on the continuous collapse performance of the existing structural system mainly focuses on the steel frame and the reinforced concrete frame, and the research on the composite beam steel frame is less. However, the simplified boundary conditions are usually adopted in the study of the joint performance in the anti continuous collapse system, and the performance of the combined joint under the joint action of bending moment and tension is less concerned. In this paper, a systematic experimental study and theoretical analysis are carried out on the continuous collapse performance of a composite beam plane steel frame and the force performance of the composite joint. The following four parts are included in this paper.
(1) the experimental study on the continuous collapse resistance of 2 four span single beam single beam plane steel frames was completed. The effect of the semi-rigid joint joint of the welded rigid composite joints on the structural system against continuous collapse was investigated. The roof load, the displacement and the horizontal displacement of the frame were measured, and the frame Liang Liangduan was obtained. And the distribution and development of the cross medium strain, the transfer process and the law of the tension and bending moment in the beam are obtained, and the influence of the beam column connection mode on the continuous collapse resistance of the composite beam plane steel frame is compared.
(2) the test of 12 steel-concrete composite joints was completed. The force mechanism of the semi rigid composite joints with rigid composite joints and half rigid composite joints under pure bending, bending and pulling were taken into consideration. The bending moment tension curve, bending moment curve and tension displacement curve of the combined joint were measured, and the beam end of the whole process was obtained. According to the experimental results and the existing theoretical analysis, the design method of the bearing capacity of the combined joint in the tension state is put forward, and the working mechanism of the combined joint in the different stage of the anti collapse during the anti collapse process is analyzed.
(3) the finite element analysis model of a composite beam with rigid connection and semi rigid connection is established by ABAQUS. The hybrid element modeling is used in the semi-rigid connection frame. Considering the bolt fracture, the force performance of the semi rigid composite joint in the structural system can be more accurately simulated. The section height of the steel beam is discussed. The influence of the thickness of concrete slab, the ratio of reinforcement and the stiffness of the joint on the continuous collapse resistance of the frame after the failure of the key column. Based on the theoretical analysis and experimental research, the simplified analysis model and the pressure arch effect model of the composite beam plane steel frame are put forward, and the calculation method of the vertical load displacement is derived.
(4) the finite element model of the three and nine storey composite beam plane steel frame was established, and the dynamic column analysis was carried out. The dynamic response and the force mechanism of the corresponding node and structure system after the failure of the key columns at different heights and positions were studied, and the influence of the influence range and connectivity on the continuous collapse resistance of the structure was determined. Finally, a simplified model which can be used to analyze progressive collapse resistance of multi-storey frame structures is proposed.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU312.3;TU398.9

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