覆板加强的方钢管T形节点轴向滞回性能试验研究

发布时间：2018-04-28 08:15

本文选题：冷弯薄壁型钢 + 方钢管　；参考：《建筑结构学报》2017年05期

【摘要】：为研究采用覆板加强的冷弯方钢管T形节点的轴向滞回性能,对2组支管与主管的截面宽度比β分别为0.4和0.8的方钢管直接焊接节点和采用覆板加强的方钢管T形节点进行了轴向往复加载试验。详细介绍了试验节点的设计、试验过程及破坏形态,并对节点试件的滞回曲线、骨架曲线、耗能和延性等性能进行了分析。试验中,试验节点经历了主管屈服、初始开裂、裂纹闭合、裂缝扩展、裂缝贯通五个主要阶段,但各试件的开裂位置并不相同。加强覆板阻止了裂缝向主管管壁发展,有效避免了主管管壁的撕裂破坏,使开裂后支管的受压荷载继续上升,因而节点开裂后受拉能力较未加强节点的好。支管与主管截面宽度比越小,试件的耗能能力和延性越好。但覆板加强处理降低了试件的耗能能力,且支管与主管宽度比越小其耗能能力的降低越明显。受拉裂缝会降低试件的延性,故轴拉循环的延性较对应的轴压循环的差。在β=0.8时,覆板加强对试件的抗震延性有所改善,但β=0.4时加强节点试件的位移延性系数低于未加强节点。覆板加强节点在支管轴向往复荷载作用下的拉压不均衡问题应引起重视。
[Abstract]:In order to study the axial hysteretic behavior of cold-formed square steel tube T-joints strengthened by overlay, The axial reciprocating loading tests were carried out for two groups of directly welded joints of square steel tube with cross section width ratio 尾 of 0.4 and 0.8 and T-joints strengthened by overlay respectively. The design, test process and failure mode of the test joints are introduced in detail. The hysteretic curves, skeleton curves, energy dissipation and ductility of the joints are analyzed. There are five main stages in the test, I. e., supervisor yield, initial cracking, crack closure, crack propagation and crack penetration, but the cracking positions of each specimen are different. The strengthened overlay prevents the crack from developing to the main pipe wall, effectively avoids the tear damage of the pipe wall, and makes the compressive load of the branch pipe continue to rise after cracking, so the tensile capacity of the joint after cracking is better than that of the joint without strengthening. The smaller the ratio of branch tube to top section width, the better the energy dissipation ability and ductility of the specimen. However, the energy dissipation capacity of the specimen was decreased with the strengthening treatment of the overlay, and the decrease of the energy dissipation capacity was more obvious when the ratio of the branch tube to the top width was smaller. The ductility of the specimen is decreased by tensile crack, so the ductility of axial tension cycle is worse than that of axial compression cycle. At 尾 0. 8, the seismic ductility of the strengthened specimens is improved, but the displacement ductility coefficient of the strengthened joints at 尾 0. 4 is lower than that of the unstrengthened joints. Attention should be paid to the unbalance between tension and compression of the reinforced joints under axial reciprocating loads.
【作者单位】：中国矿业大学深部岩土力学与地下工程国家重点实验室;江苏建筑职业技术学院;中国矿业大学江苏省土木工程灾变与结构可靠性重点实验室;
【基金】：国家自然科学基金项目(51408596) 江苏省自然科学基金项目(BK20140195) 江苏建筑节能与建造技术协同创新中心开放基金项目(SJXTY1510,SJXTY1609)
【分类号】：TU392.3

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