梁柱弱轴连接翼缘削弱型节点的试验研究和有限元分析

发布时间：2019-06-10 21:32

【摘要】：1994年美国北岭地震和1995年日本阪神地震中，曾经被认为具有良好抗震性能的钢框架梁柱连接处发现了大量的脆性断裂。震后人们对钢框架梁柱连接抗震性能进行了大量研究，提出了一种新型延性节点—翼缘削弱型节点(RBS)。翼缘削弱型节点的设计思路是，对距梁柱连接处一定距离的梁截面进行局部削弱，促使塑性铰在梁削弱位置出现并扩展，避开节点域焊缝密集区，避免节点发生脆性破坏，提高节点延性性能。目前国内外对翼缘削弱型节点的研究主要集中在梁柱强轴连接，对梁柱弱轴连接研究较少。为此，本文对钢框架梁柱弱轴栓焊混合连接翼缘削弱型节点开展了试验研究和有限元分析。本文在参考国内外文献资料的基础上，设计了3个钢框架梁柱弱轴栓焊混合连接翼缘削弱型节点试件，进行了低周反复荷载作用下的试验研究，研究了节点的破坏形态、滞回性能、承载力等。作为对比，还设计了一个普通节点试件。试验在梁端施加低周往复荷载，4个试件的破坏形态相似，焊缝通过孔处的梁翼缘首先屈曲，进而在焊缝通过孔处出现裂缝并扩展，导致试件的承载力下降并破坏，破坏位置在焊缝通过孔处的梁端。对削弱试件而言，塑性铰没有在梁削弱位置出现。试件破坏的主要原因是焊缝通过孔切割过大、表面粗糙，导致焊缝通过孔处产生应力集中。研究结果表明：焊缝通过孔的大小和切割好坏对试件破坏及塑性铰的出现有重要影响；试验中钢框架梁柱弱轴栓焊混合连接翼缘削弱型节点与普通节点相比，滞回曲线稍显丰满，滞回环面积稍大些，说明削弱参数如设置不当，未必能有效提高塑性耗能能力。基于3个翼缘削弱型节点试件和1个普通节点试件试验研究基础上，利用有限元软件ABAQUS对试验试件进行了数值模拟分析，考虑了材料非线性、几何非线性，研究了翼缘削弱型节点的破坏形态、滞回性能、承载力等。有限元分析结果和试验结果较吻合。由于焊缝通过孔处梁翼缘无腹板支撑，产生局部屈曲，试件在梁端破坏，没有实现塑性铰外移。分析结果表明：焊缝通过孔对削弱试件的破坏形态和塑性铰的出现有重要影响；试验结果和有限元分析均显示削弱试件与普通试件相比，承载力有所下降，所以在试件设计时翼缘削弱对承载力下降的影响不能完全忽略；梁翼缘有、无削弱以及焊缝通过孔对试件关键部位应力变化影响很大。此外，为了考虑焊缝通过孔对试验试件的影响，对试验试件进行了改进，设计了无焊缝通过孔翼缘削弱型节点试件和梁拼接点焊缝通过孔在削弱位置外侧翼缘削弱型节点试件，同样利用有限元软件ABAQUS进行数值模拟分析。分析结果表明：无焊缝通过孔和梁拼接点焊缝通过孔在削弱位置外侧的翼缘削弱型节点试件均实现了塑性铰外移，与普通试件相比，具有较强的耗能性能、延性性能；为有效实现翼缘削弱型节点塑性铰外移，，建议焊缝通过孔设置在削弱位置外侧，或者不设焊缝通过孔。
[Abstract]:A lot of brittle fracture was found at the joint of the steel frame and column, which had been considered to have good anti-seismic performance in the northern part of the United States in 1994 and the earthquake of the Japanese earthquake in 1995. After the earthquake, the anti-seismic performance of the beam-column connection of the steel frame is studied in a large scale, and a new type of ductile-node fin-edge weakening-type node (RBS) is proposed. The design idea of the flange-weakening type node is that the section of the beam at a certain distance from the joint of the beam-column is partially weakened, and the plastic hinge is caused to appear and expand at the weakened position of the beam, so as to avoid the dense area of the welding seam of the node, so that the brittle failure of the node can be avoided, and the ductility performance of the node is improved. At present, the research of the flange-weakening type node at home and abroad is mainly focused on the beam-column strong shaft connection, and the connection of the beam-column weak shaft is less. In this paper, the experimental research and the finite element analysis of the flange-weakened joints of the steel frame beam-column weak-shaft bolt-welded joint are carried out. On the basis of reference to the domestic and foreign literature, this paper designs 3 steel frame beam-column weak-shaft bolt-welded joint flange-weakening type node test piece, and carries out the test research under the action of low-cycle repeated load, and studies the failure mode, the hysteretic behavior, the bearing of the node, in contrast, a common node is also designed The test piece shall be tested at the beam end with low-cycle reciprocating load. The failure mode of the four test pieces is similar. The beam flange at the passing hole of the weld joint is first buckled, and then the crack and expansion at the passing hole of the welding line cause the bearing capacity of the test piece to drop and break, and the damage position is at the through hole of the weld joint. The beam end. The plastic hinge is not in the beam weakening position for the weakened test piece The main reason for the failure of the test piece is that the weld is cut too large through the hole, the surface is rough, causing the weld to generate stress through the hole The results show that the size and the cutting of the weld seam have an important influence on the failure of the test piece and the appearance of the plastic hinge. Large, indicating that the weakening parameter, such as improper setting, may not be effective to improve the plastic energy consumption On the basis of three flange-weakening type node test piece and one common node test piece test, the finite element software ABAQUS is used to simulate the test piece, and the nonlinear and geometric nonlinearity of the material is considered, and the damage form of the edge weakening type node is studied. hysteretic behavior , bearing capacity, etc. Finite element analysis results and tests The result is in good agreement. Because the welding seam is not supported by the web at the beam flange at the hole, the local buckling is generated, and the test piece is damaged at the end of the beam and is not implemented. The results of the analysis show that the test results and the finite element analysis show that the load bearing of the test piece is less than that of the normal test piece. The force has decreased, so the influence of flange weakening on the bearing capacity is not completely ignored in the design of the test piece; the flange of the beam is not weakened and the stress of the key part of the test piece is changed through the hole In addition, in order to consider the influence of the weld through the hole on the test piece, the test piece is modified, and the weld through the hole flange weakening type node test piece and the beam splicing point weld joint is designed through the hole in the weakened position. Edge-weakening-type node test piece, also using the finite element software ABAQUS The numerical simulation is carried out. The results of the analysis show that the weld of the weld through the hole and the joint of the beam through the hole and the edge of the flange at the outer side of the weakened position can be removed by the plastic hinge, and it has stronger consumption compared with the common test piece. the performance and the ductility performance of the flange are effectively realized; the plastic hinge of the flange weakening type node is effectively realized, and the welding seam is recommended to be arranged on the outer side of the weakening position through the hole o
【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】：TU391

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