【作者】 李健；

【导师】 王莉萍； 康艳博；

【作者基本信息】 中南大学 ， 土木水利（专业学位）， 2023， 硕士

【摘要】 在“碳达峰、碳中和”理念下,装配式钢结构建筑因其生产工艺的优势而具有广阔的发展空间。梁柱连接节点是影响钢框架结构安全性和可靠性的重要组成部分。冷弯型钢具有较高的强度重量比与灵活的截面形式,可在多层钢结构建筑中产生较高的经济效益。目前我国关于冷弯型钢结构的研究相对滞后,对于其抗震性能方面的研究少之又少。在此基础上,本文提出了一种新型冷弯型钢双肢拼合梁与冷弯型钢钢管柱螺栓连接装配式梁柱节点形式,采用拟静力试验与有限元模拟相结合的方式,对节点的抗震性能进行了研究,主要工作及结果如下:(1)设计制作了4个新型冷弯型钢装配式梁柱节点足尺试件,采用梁端加载形式,开展了节点在低周往复荷载下的拟静力试验研究。结果表明:节点试件的主要破坏模式为双肢拼合梁最外排螺栓孔截面翼缘及卷边的屈曲变形与螺栓孔的塑性变形。节点试件的滞回曲线呈现“反S形”,存在明显的“滑移段”,滞回环包络面积较大,节点的耗能能力良好。节点试件的刚度退化明显,强度退化较小,延性系数为3.13～3.48,等效粘滞阻尼系数为0.13～0.17,高强螺栓的滑移作用对节点的耗能与变形均有一定影响。(2)通过有限元软件ABAQUS/Standard 6.20建立了新型冷弯型钢装配式梁柱节点的有限元模型,从破坏模式与滞回曲线两方面通过与试验结果比对的方式进行了有限元模型验证,整体吻合度较高。在此基础上,通过改变节点域的拼合梁连接长度、高强螺栓规格以及拼合梁腹板连接板间距,对影响节点抗震性能的参数进行了分析,结果表明:增加节点域的双肢拼合梁连接长度可以增强节点的承载能力与耗能能力,连接长度以1倍梁高为宜;增大节点域高强螺栓规格可以增强节点前期的耗能能力,对于节点的承载能力影响不大,螺栓规格以M16为宜;拼合梁腹板连接板间距对于节点后期的承载力下降速度有一定影响,间距取值以2倍梁高为宜。(3)采用试验拟合法,建立了节点试件的无量纲化三折线骨架曲线模型与恢复力模型,经过回归分析得到了冷弯型钢装配式梁柱节点在低周往复荷载作用下的刚度退化规律,并与试验结果进行了比较验证。图48幅,表7个,参考文献103篇更多还原

【Abstract】 Under the background of the carbon peak and neutrality,the prefabricated steel structures have a good development prospect due to the advantages of their production process,and the beam-column joint connection is a vital component that affecting the safety and reliability of the steel structure.Cold-formed steel sections have the high ratio of strength-weight and the flexible section-form,which can generate high economic benefits in use of multi-storey steel structures.At present,the research on cold-formed steel structure is relatively lagging in China,and the research on its seismic performance is rare.On the basis of above,a new type of prefabricated cold-formed steel double limb built-up beam-square column joint was proposed in this paper.The seismic behavior of the joint was studied through the quasistatic cyclic loading test and the finite element simulation.The main work and results are as follows:(1)Four full-scale specimens of the new type prefabricated coldformed steel beam-column joints were designed and manufactured,and the quasi-static tests were carried out on the joint specimens through the beam-end low cyclic loading mode.The test results show that the main failure modes of joint specimens were the buckling deformation of flange and lip of outermost bolt-hole section and the plastic deformation of bolt holes of double limb built-up beams.The hysteresis curves of the joint specimens were all in the shapes of inverse-S with the obvious slip sections.The envelope areas of the hysteresis loops were large which meant that the energy dissipation capacity of the joint was good.The joint specimens presented the obvious degradation in stiffness and relatively lower degradation in strength.The ductility coefficients of the joint specimens were between 3.13 to 3.48,and the equivalent damping coefficient was between 0.13 to 0.17.The slippage of high-strength bolts will affect the performance of energy-dissipation and deformation of the joint.(2)The finite element analysis models of joints were established through ABAQUS.The FEA results of the specimens were in good agreement in the comparison with the test results,which verified the feasibility of FEA methods.On the basis of that,by changing the number of high-strength bolts in the joint area,the specification of high-strength bolts and the spacing between the connecting plates of the web of double limb built-up beams,the preliminary analysis of the parameters those affect the seismic behavior of the joint was carried out.From above,the conclusions were following: Increasing the connection length of the double limb built-up beams in the joint area could enhance the bearing capacity and energy dissipation capacity of the joint,and the connection length should be close to the beam height.Increasing the specification of high-strength bolts in the joint area could enhance the energy dissipation capacity of the joint in the early stage,yet barely affected the bearing capacity of the joint,and the bolt specification should be M16.The distance between the connecting plates of the web of double limb built-up beams had certain influence on the descending speed of bearing capacity of the joints in the later stage,and the value of the spacing could be the twice of the beam height.(3)Trilinear skeleton curve model and restoring load-displacement model of joint specimens were established through the test fitting method.The stiffness-degradation law of prefabricated cold-formed steel beam-column joint under low cyclic load was obtained by regression analysis and verified by comparison with the test results.更多还原