肋板及翼缘板加强节点抗震性能有限元分析

发布时间：2018-09-04 12:50

【摘要】：传统的梁柱连接节点在地震中易发生脆性破坏，在美国和日本的两次地震后，各国学者通过理论分析和试验研究提出了一种新型节点——加强型节点。加强型节点是一种典型的将塑性铰外移的节点形式，加强型节点包括：板式加强节点、肋板加强节点、腋板加强节点等。本文的研究集中在非对称和对称肋板加强、翼缘板加强等三种加强型节点，主要内容包括： 1、在国内外对肋板及翼缘板加强节点研究的基础上，参考美国钢结构设计指南AISC Design Guide12、美国规范FEMA-350建立了有限元模型，分析了模型在低周往复荷载作用下的各项抗震性能，并与试验结果相互对比。结果表明，二者各方面的抗震性能基本吻合，验证了试验研究的有效性与有限元分析的正确性。 2、在以上分析的基础上，建立了肋板及翼缘板长度变化的三组与肋板高度、厚度变化的各两组共43个有限元模型，将有限元模拟结果分别从应力发展和变形规律、滞回性能、骨架曲线与承载力、延性性能和耗能能力等方面对肋板及翼缘板几何尺寸改变时节点抗震性能的影响进行了详细的分析。结果表明，各有限元模型都能使塑性铰有效地外移；增加肋板及翼缘板长度可以提高节点的极限承载力并提升节点的滞回性能，但会降低节点的延性和耗能能力，而且肋板及翼缘板长度太长或太短都对节点域的应力发展不利，所以建议肋板及翼缘板长度取值为0.7倍梁高；增加肋板高度虽然可使节点域的受力情况更理想，但是肋板较高的节点在延性和耗能能力方面并不理想，而且节点极限承载力、滞回性能的提升也并不明显，过高的肋板也会露出上层混凝土楼板，影响美观，所以建议肋板高度取值为0.55倍肋板长度；增加肋板厚度可使节点受力性能更好，但是在节点的延性性能和耗能能力方面，肋板较厚的试件表现并不理想，而且过厚的肋板会增大节点焊接残余应力，使节点造成质量缺陷，，也会加大焊接的难度，所以建议肋板厚度（双肋板则取总厚度）取值为1.5倍梁翼缘厚度。 3、针对有限元分析结果，进行了非对称肋板加强节点、对称肋板加强节点、翼缘板加强节点等三种节点之间各方面抗震性能的综合对比分析。结果表明，对称肋板加强节点的性能要优于非对称肋板加强节点和翼缘板加强节点。
[Abstract]:The traditional Liang Zhu connection joints are prone to brittle failure in the earthquake. After the two earthquakes in the United States and Japan, scholars from various countries put forward a new type of node-enhanced node through theoretical analysis and experimental research. The reinforced joint is a typical type of joint which moves the plastic hinge out of the joint. The enhanced joint includes the plate reinforced joint, the ribbed plate strengthened joint, the axillary plate strengthened joint and so on. This paper focuses on three kinds of strengthened joints: asymmetric and symmetrical stiffened ribbed plate and flange plate. The main contents are as follows: 1. On the basis of research on stiffened joints of ribbed and flange plates at home and abroad. A finite element model is established with reference to the American steel structure design guide AISC Design Guide12, American Code FEMA-350. The seismic behavior of the model under low cyclic reciprocating loads is analyzed and compared with the experimental results. The results show that the aseismic performance of the two methods is basically consistent, which verifies the validity of the experimental study and the correctness of the finite element analysis. 2. On the basis of the above analysis, A total of 43 finite element models are established for the length variation of ribbed plate and flange plate, the height and thickness of ribbed plate. The results of finite element simulation are derived from stress development and deformation law, hysteretic property, skeleton curve and bearing capacity, respectively. In the aspects of ductility and energy dissipation capacity, the effect of joint seismic behavior on the joint seismic behavior when the geometric size of ribbed plate and flange plate is changed is analyzed in detail. The results show that each finite element model can make plastic hinge move out effectively, and increasing the length of ribbed plate and flange plate can improve the ultimate bearing capacity and hysteretic performance of joints, but reduce the ductility and energy dissipation capacity of joints. The length of ribbed plate and flange plate is too long or too short, so it is suggested that the length of ribbed plate and flange plate should be 0.7 times of beam height. But the joint with high ribbed slab is not ideal in ductility and energy dissipation, and the ultimate bearing capacity and hysteretic performance of the joint are not obvious. Therefore, it is suggested that the height of ribbed plate should be 0.55 times the length of ribbed plate, and that increasing the thickness of ribbed slab can make the joint have better mechanical performance, but in the aspect of ductility and energy dissipation capacity of joint, the specimen with thicker ribbed plate is not satisfactory. And too thick ribbed plate will increase the welding residual stress of the joint, cause the quality defect of the joint, and also increase the difficulty of welding. Therefore, it is suggested that the thickness of rib plate (the total thickness of double rib plate) should be 1.5 times the thickness of beam flange. 3. According to the results of finite element analysis, an asymmetric stiffened ribbed plate joint is carried out. Comprehensive comparison and analysis of seismic performance among three kinds of joints such as flange plate reinforced joints. The results show that the performance of symmetrical stiffened ribbed joints is better than that of asymmetric stiffened ribbed joints and flange plate strengthened joints.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU352.11;TU391

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