新型混合连肢墙节点抗震性能研究

发布时间：2018-12-21 13:04

【摘要】：采用钢连梁代替原有的钢筋混凝土连梁，形成混合连肢墙体系。钢连梁按照偏心支撑钢框架耗能梁段进行设计，它结合了钢梁变形能力强、混凝土剪力墙侧向刚度大的优点，更加适用于高抗震设防烈度地区，其独特的优越性得到科研工作者的高度重视。钢连梁与剪力墙的连接节点对于保证混合连肢墙体系的抗震性能至关重要。但以往的研究主要集中在钢连梁直接插入剪力墙的直埋式节点，本课题组提出在钢筋混凝土剪力墙的边缘构件中设置适当的型钢柱，钢连梁与钢柱进行全焊连接的新型节点形式。通过试验研究、有限元分析和理论分析对这种新型节点在循环荷载作用下的破坏机理进行了研究，提出了相应的抗震设计方法。为研究这种新型节点的抗震性能，进行了“强节点弱梁”和“弱节点强梁”两类共6个足尺节点试件的低周反复加载试验。观察了节点的破坏形态，并对试件的破坏机理、滞回性能、承载能力、耗能能力、变形组成以及各参数的影响进行了分析。试验结果表明：强节点试件滞回曲线呈纺锤形，具有良好的抗震性能，类似于偏心支撑钢框架耗能梁段的性能，能很好地解决混凝土连梁配筋困难、小跨高比连梁延性不足的问题；弱节点试件破坏形态为剪切破坏，与钢梁-型钢混凝土柱节点的破坏形态类似，延性和耗能能力比普通混凝土节点优越。基于试验研究结果，利用有限元软件ABAQUS对试件进行了低周反复荷载作用下的有限元模拟，选用合适的拉、压损伤本构模型并考虑了钢与混凝土之间的粘结滑移，将计算结果和试验结果进行对比，两者吻合较好。在此基础上对弱节点模型进行了参数分析，主要研究了节点域钢腹板高度和厚度、箍筋直径、水平分布筋直径、轴压比、混凝土强度、是否设置面承载板等参数对节点滞回性能的影响。根据试验和有限元分析结果分析了新型混合连肢墙节点的受力机理，对型钢混凝土暗柱的边界条件进行了力学简化，将复杂的新型混合连肢墙节点转化为已有一定研究成果的钢梁与型钢混凝土柱节点，提出了计算混合连肢墙节点水平剪力的计算模型，得到了节点核心区水平剪力的计算公式。参考已有的研究成果，给出了节点的抗剪承载力计算公式，将试验及有限元分析结果与公式计算结果进行对比，吻合较好。提出了剪切屈服型钢连梁与弯曲屈服型钢连梁的极限承载力公式，并结合节点核心区极限承载力公式设计了两个节点试件，通过有限元计算，，证明了计算公式的准确性。
[Abstract]:The steel connecting beam is used instead of the original reinforced concrete connecting beam to form the mixed multi-limb wall system. The steel-connected beam is designed according to the energy dissipation beam section of eccentrically braced steel frame. It combines the advantages of strong deformation ability of steel beam and large lateral stiffness of concrete shear wall, so it is more suitable for high seismic fortification area. Its unique superiority is highly valued by researchers. The connection joint between steel beam and shear wall is very important to ensure the seismic performance of hybrid wall system. However, previous studies mainly focused on the direct-buried joints in which steel beams were directly inserted into shear walls. Our group proposed that appropriate steel columns should be installed in the edge members of reinforced concrete shear walls. A new type of joint for full welding of steel-connected beams and columns. Through experimental research, finite element analysis and theoretical analysis, the failure mechanism of this new type of joint under cyclic load is studied, and the corresponding seismic design method is put forward. In order to study the seismic behavior of this new type of joints, the low-cycle repeated loading tests of six full-scale joint specimens were carried out, namely, "strong joints with strong joints" and "strong beams with weak joints". The failure mechanism, hysteretic performance, load-carrying capacity, energy dissipation capacity, deformation composition and the influence of the parameters of the specimens were analyzed. The test results show that the hysteretic curve of the strong joint specimen is spindle-shaped and has good seismic performance, which is similar to the performance of the eccentrically braced steel frame with energy dissipation beam, and can solve the problem of reinforced concrete connecting beam. The ductility of small span ratio connecting beam is insufficient; The failure mode of weak joint specimens is shear failure, which is similar to that of steel beam-steel reinforced concrete column joints, and the ductility and energy dissipation capacity are superior to those of ordinary concrete joints. Based on the experimental results, the finite element simulation of specimens under low cyclic loading is carried out by using the finite element software ABAQUS. The appropriate constitutive model of tensile and compressive damage is selected and the bond-slip between steel and concrete is considered. The calculated results are in good agreement with the experimental results. On this basis, the parameter analysis of the weak joint model is carried out. The height and thickness of steel web plate, the diameter of stirrups, the diameter of horizontally distributed bars, the axial compression ratio, the strength of concrete in the joint domain are studied. Whether or not to set the surface bearing plate and other parameters on the hysteretic performance of the joint. Based on the results of test and finite element analysis, the mechanical mechanism of the new type of composite wall joints is analyzed, and the boundary conditions of the steel reinforced concrete (SRC) dark columns are simplified by mechanics. In this paper, the complex new hybrid wall joints are transformed into the steel beam and steel reinforced concrete column joints which have been studied. A model for calculating the horizontal shear force of the joint is proposed, and the formula for calculating the horizontal shear force in the core area of the joint is obtained. With reference to the existing research results, the formulas for calculating the shear capacity of joints are given. The results of test and finite element analysis are compared with those of the formulas, and the results are in good agreement. The ultimate bearing capacity formula of shear yield steel connecting beam and bending yield steel connecting beam is put forward, and two joint specimens are designed in combination with the ultimate bearing capacity formula of the core zone of joint. The accuracy of the calculation formula is proved by finite element calculation.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU352.11

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