混凝土柱-蜂窝钢梁组合节点拟静力试验研究

为研究复合焊接环式箍筋混凝土柱-蜂窝钢梁组合节点的受力性能。对四种不同连接形式的8个复合焊接环式箍筋混凝土柱-蜂窝钢梁组合节点试件进行了低周反复荷载作用下的拟静力试验,分析了各节点的破坏形态、承载力、受剪性能、延性、耗能性能、滞回特性等。试验结果表明:试件的承载力与节点核心区的配箍率有关,对于钢梁贯通型的梁柱节点,宜加强节点核心区的箍筋配置,有利于提高试件的承载力和延性;外伸式端板连接型试件的承载力最高,但在极限荷载之后出现严重的刚度退化,耗能能力差;核心区加设箍筋的钢梁贯通型试件的承载力、延性和耗能能力均比较好,抗震性能好,能够满足工程实践的要求。     

外伸式端板连接蜂窝钢梁-混凝土柱组合节点抗震性能试验研究

通过7个1∶2比例外伸式端板连接蜂窝钢梁-混凝土柱组合节点的低周反复加载试验,研究不同螺栓数目、直径及排列方式的外伸式端板连接蜂窝钢梁-混凝土柱组合节点在各受力阶段的抗震性能和合理的节点构造形式。基于试验数据,分析了节点在反复荷载作用下的破坏形态、滞回曲线、骨架曲线、刚度退化、延性和耗能性能等。试验结果表明：试件的破坏形态和变形与螺栓数目、直径及排列方式有关,外伸端板螺栓连接中螺栓数目多、直径大的节点连接形式的承载力高,抗震性能较好;8个端板螺栓4行2列的排列形式为最合理的抗震节点形式;外伸端板螺栓数量为8个时的延性和耗能性能都能满足抗震的要求。     

部分包裹混凝土柱与型钢梁连接节点的抗震性能研究

本文对部分包裹混凝土柱与型钢梁外伸端板连接节点的抗震性能进行了试验研究。共设计了4个构造不同的梁柱节点,通过施加低周反复水平荷载,研究该节点各连接组件板域的应变分布及破坏模式,分析端板厚度、加劲板、背垫板对节点承载力、刚度、延性及耗能性能的影响。     

复式钢管混凝土柱与H形钢梁连接节点抗震性能试验研究

借鉴方钢管混凝土柱-钢梁外肋环板节点形式,将非梁柱连接面的柱两侧外肋环板改为竖贴于柱侧的竖向肋板并伸出与梁翼缘焊接,同时设置锚固腹板,形成复式钢管混凝土柱与H形钢梁连接节点。通过7个梁柱组合体试件的低周反复荷载试验,分析各试件的破坏过程及特征,并对试件的滞回性能、承载力、延性、耗能能力和承载力及刚度退化等抗震性能进行研究。研究结果表明：节点的破坏形态基本相同,梁端先屈曲,形成塑性铰;锚固腹板可有效提高节点的承载力和变形能力;竖向肋板外伸长度可提高试件的初始刚度,使梁端塑性铰外移,有效保护节点核心区;试件的滞回曲线呈明显的梭形,具有良好的承载力、延性及耗能能力;试件在整个加载过程中刚度退化现象明显,承载力退化很小,可应用于抗震设防地区。     

SC梁与CCSHRC柱端板螺栓连接节点试验

为了验证钢与混凝土组合梁（SC梁）与高强复合连续螺旋箍约束钢筋混凝土柱（CCSHRC柱）节点的受力机理及抗震性能,对足尺的端板螺栓连接的SC梁与CCSHRC柱节点试件进行了低周反复荷载试验,对节点的抗震受剪承载力进行了分析,并根据试验结果得到了节点核心区抗震受剪承载力的计算公式。结果表明:组合节点受力合理,破坏前梁端形成明显的塑性铰,同时由于高强螺栓预压力的存在以及钢板箍的约束作用,使得核心区混凝土处于三轴受压应力状态,抗震受剪承载力显著提高,大大改善了节点区的抗剪能力,同时也增大了节点的刚度,所得抗震受剪承载力的计算公式可供实际工程参考。     

多层钢框架半刚性端板连接的循环荷载试验研究

为研究多层钢框架半刚性梁柱端板连接的抗震性能,对8个不同构造端板连接足尺试件进行了循环荷载试验研究, 分析了端板厚度、螺栓直径、端板外伸加劲肋、柱腹板加劲肋、平齐式和外伸式等因素对节点承载力、转动刚度、极限转动 能力、耗能能力、延性和极限破坏状态的影响。试验结果表明,半刚性梁柱端板连接具有良好的延性和耗能能力,可以应用 于多层抗震钢框架中。根据试验结果及相关分析,提出了多层抗震钢框架中端板连接的标准构造为:两端外伸,设置柱腹 板加劲肋和三角形端板加劲肋,柱翼缘在端板外伸边缘上下各100mm范围内局部加厚,厚度与端板厚度相同。对提高端 板连接节点的抗震性能提出了宜采用大直径螺栓、中等厚度端板的设计建议。本文还在"强节点,弱构件"抗震设计一般原 则的基础上提出了"强连接,弱板件"的端板连接抗震设计概念。     

预制混凝土管组合柱-钢梁连接节点抗震性能试验研究

为研究预制混凝土管组合柱-钢梁连接节点的抗震性能,以轴压比、钢套箍延伸高度、芯部混凝土强度以及钢套箍厚度为主要参数,进行了6个1/2缩尺节点的拟静力试验。研究了各节点的破坏形态、滞回特性、承载能力、耗能能力以及节点域受剪性能。试验结果表明：各节点主要破坏模式均为节点域剪切破坏;滞回曲线呈典型弓形,耗能能力较好;芯部混凝土强度和钢套箍厚度是影响节点抗震性能的关键参数,对承载能力和耗能性能影响较大;破坏时节点域极限剪切变形介于0.0482 ~0.100 rad之间;节点域受剪承载力降低系数介于0.86~1.00之间,承载力退化性能稳定。建立了预制混凝土管组合柱-钢梁连接节点受剪承载力计算式,计算值与试验值吻合较好且偏于安全。     

钢管混凝土组合节点的抗震性能及其影响因素研究

为研究钢管混凝土柱节点的抗震性能及其影响因素,采取柱端加载模式进行了4组钢管混凝土柱单边螺栓端板连接节点的拟静力加载试验,考察了柱截面空心率和端板连接形式对节点破坏模式、柱端载荷-位移滞回曲线、弯矩-转角关系曲线和耗能能力的影响。结果表明,平齐端板连接和外伸端板连接节点试件的破坏模式基本相同,都包含端板屈曲变形、M16螺栓出现部分滑移、梁端翼缘屈曲变形、局部栓钉剪切破坏、楼板柱根部出现裂缝和柱边混凝土破坏的过程;平齐端板和外伸端板连接节点试件,在加载过程中都未出现屈曲变形或者破坏,说明钢管混凝土柱在较大侧向位移作用下,具有较好的抵御撕裂和屈曲变形的能力;在相同空心率条件下,平齐端板连接节点柱边缘的裂缝相较于外伸端板连接节点试件更少,外伸端板连接节点试件的极限承载力、耗能能力、正向载荷和负向载荷作用下的极限承载力和初始刚度、正弯矩和负弯矩作用下的抗弯承载力和初始转动刚度要高于平齐端板连接节点试件;在相同端板连接条件下,空心率较低的节点试件的极限承载力、耗能能力、正向载荷和负向载荷作用下的极限承载力和初始刚度、正弯矩和负弯矩作用下的抗弯承载力和初始转动刚度要高于空心率较高的节点试件。在极限状态下,4种节点试件的等效粘滞阻尼系数ξ_c都保持在0. 204～0. 235之间,耗能能力优于钢筋混凝土柱节点,并与钢管混凝土柱外加强环节点的耗能能力相当,4种节点试件具有较强的耗能能力。     

地震作用下端板抗弯连接的受力性能

该文进行了8个足尺钢梁柱端板抗弯连接节点在循环荷载下的试验研究。试验考察的参数有端板厚度、螺栓直径、端板外伸加劲肋、柱加劲肋、端板类型（齐平端板及外伸端板）。试验给出了端板连接节点的弯矩承载力、转动刚度、转动能力及滞同曲线结果。试验结果表明外伸端板连接具有抗震框架所要求的足够的承载力、节点转动刚度、延性及耗能能力。基于试验结果和理论分析,提出了抗震框架端板连接的节点构造,推荐给出了三种破坏模式需求及相应的承载力,     

混凝土异形柱-钢梁装配式节点受剪性能试验研究

为研究混凝土异形柱-钢梁装配式框架节点核心区的受剪性能,按照预制混凝土异形柱中预埋钢牛腿节点未加强、增配X形筋、增配X形钢板三种方式,分别制作3个预制混凝土异形柱-钢梁节点试件进行拟静力试验,得到其破坏特征、承载力、滞回曲线、刚度退化、耗能能力等抗震性能指标。由节点剪切变形、节点区钢筋应变、钢板应变测量结果,分析了不同牛腿加设方式对节点核心区受力性能的影响。结果表明：试件位移延性系数在3.22~5.94之间,破坏时位移角都超过1/50,抗震性能良好;牛腿内侧加设的X形钢筋与X形钢板均与节点核心区混凝土协同受力,可有效提高节点核心区受剪承载力。采用有限元软件ABAQUS对采用X形钢板增强的试件进行了数值模拟和参数分析,依据试验分析结果,推导出X形钢板增强的预制异形柱-钢梁混合装配式框架节点核心区受剪承载力计算公式,计算结果与试验实测值和有限元模拟值吻合较好。     

Q690高强钢外伸端板加劲螺栓连接节点抗震性能试验研究

为研究高强钢外伸端板加劲螺栓连接节点的抗震性能和设计方法,基于EC3规范组件法和同步塑性设计理念,设计了3种不同屈服机制的Q690高强钢外伸端板加劲螺栓连接节点,通过循环加载试验研究了节点的破坏模式、刚度和承载力、耗能能力以及应变分布规律等,进一步验证了节点能力设计计算模型的有效性.研究结果表明:高强钢外伸端板加劲螺栓...     

Experimental investigation on flush end-plate bolted composite connection in fire

Three tests at elevated temperatures were carried out to invest the fire-resistant capacity of flush end-plate composite joints. The axial force was considered in two of the three tests simulating fire conditions to investigate its effect on the connection's load carrying ability (one with fire protection and the other without fire protection). Summaries have been given on the failure mechanisms, temperature distribution, loading carrying capacity of the composite joint and the mutual influence between joints and beams at elevated temperatures. Date shows that the failure mode of the flush end-plate joint without stiffener is usually dominated with the yielding of the bottom flange of steel beam near the supports, elements of the composite connection have different rate of temperature increase, and the axial force from restrained composite beam influences the rotational stiffness and moment capacity of joints. This paper also theoretically presents how the interaction of joints and beam developed in fire conditions. A practical simplified method is proposed to calculate the non-linear variable characteristics of composite connection in the analysis of catenary action of beams at elevated temperatures. The proposed method is verified by the experimental investigations. This study offers a feasibility of fire-resisting design and evaluation for the composite beam with semi-rigid connections in the complete temperature range.     

螺栓端板连接节点的三维非线性有限元分析

通过对不同厚度的螺栓端板连接节点的三维非线性有限元分析 ,全面研究和探讨了端板对于节点初始连接刚度 ,梁的延性破坏以及本身接触状态的影响 ,从而为这种节点的正确设计提供参考。     

Numerical study on seismic behaviors of steel frame end-plate connections

In order to study the seismic behaviors of steel frame end-plate connections, an efficient and accurate finite element model of ABAQUS was established subjected to cyclic loadings. Element types, material cyclic constitutive models and contact models for bolts, end plate and members were described. Geometry and material nonlinearity were adequately considered. The simulated results of numerical models were verified by typical quasi-static tests of end-plate connections, including both hysteretic curves and failure modes. It provided a strong tool for investigating the performances of this kind of connection. Based on the verified models, connections with different connection methods were established to investigate the effect of connection methods on behaviors of connections, including fully welded connection, extended end-plate connection and flush end-plate connection. The carrying capacity, initial stiffness, hysteretic behaviors, degraded characteristics, fracture tendency index, failure modes and energy dissipation capacity were compared and discussed in depth. The results showed that: If the beam and column are reliably connected, the extended end-plate connection can obtain the same ultimate carrying capacity and initial stiffness (monotonic behaviors) as the welded connection, however, their hysteretic curves, degradation developing curves, and fracture tendency were quite different. It indicated that the connection methods could significantly affect the cyclic behaviors. The stiffeners of end-plate connection could be treated as the first defense of connection, effectively changing the failure mode and avoiding brittle fracture. Therefore, in the high seismic zones, hysteretic behaviors, failure modes and seismic ductility should be taken into account comprehensively to choose the appropriate connection methods.     

方钢管钢骨混凝土柱与钢梁端板螺栓连接节点抗震性能试验研究

为研究方钢管钢骨混凝土柱与钢梁端板螺栓连接节点的抗震性能,进行了5个节点拟静力试验研究,分析了端板厚度、螺栓直径、混凝土强度和轴压比等因素对承载力、弯矩-转角曲线、耗能能力、承载力衰退、刚度退化、延性以及破坏模式的影响。研究结果表明：方钢管钢骨混凝土柱与钢梁端板螺栓连接节点均属于半刚性节点,初始转动刚度随着端板厚度和螺栓直径增大而提高,但节点的极限转动能力随着端板厚度的增大而减小;当承载力由端板或钢梁控制时,其具有良好的转动和耗能能力;试件承载力退化系数在0.8～1.0之间,变化幅度不大,刚度退化相比荷载退化严重;设计中应避免高强螺栓发生脆性破坏。     

钢板攻丝高强螺栓连接钢框架节点力学性能试验研究

对采用钢板攻丝高强螺栓连接的钢框架节点分别进行了高强螺栓拉伸及剪切试验、钢柱法兰连接节点静力及拟静力试验、梁柱半刚性连接静力试验.基于试验数据对节点连接的承载能力、失效模式以及刚度特征等关键问题进行了分析.研究结果表明:由自攻螺纹钢板及高强螺栓构成的连接形式具有良好的抗拉、抗剪性能,以螺杆断裂为最终破坏模式;钢柱法兰连...     

火灾中端板连接的模拟单元

采用2结点连接单元模拟高温下的端板螺栓连接。该单元允许在参考平面设置单元结点,参考平面中连接内部温度分布不均匀。考虑了由于弯曲、轴拉、轴压及剪切引起的连接破坏,并考虑了轴拉力对连接的影响。本模型兼具简化模型和组合模型的优点。进行23组耐火试验,验证模型的正确性。结果表明:本模型可用于分析火灾下端板螺栓连接性能,具有足够可靠度。与试验相比,本模型偏保守,可用于进行钢框架组合结构的耐火设计。借助本思路,可设计其他连接形式,如简单连接,柱连接及中空截面连接等。     

Numerical and analytical investigations of steel beam-to-column joints at elevated temperatures

Several furnace tests on the behavior of steel beam-to-column end-plate joints at high temperatures have been reported in a previous paper. This paper presents a series of corresponding analytical and numerical investigations to study the behavior of these steel joints, in some cases taking account of the influence of thermal restraint. A “component-based” methodology has been utilized to analyze the mechanical response of steel end-plate joints at elevated temperatures, incorporating the beam web shear component together with those within the tension and compression zones of the connection. Effects from thermal restraints on steel joints have also been integrated into this approach. This analytical model was found to represent well the structural behavior in the tests, including the effects of thermal restraint. In order to set these results into their proper context, detailed finite element simulations of the tests were also performed. Both the component-based and numerical predictions provide acceptable correlations with the test behavior.     

门式刚架梁柱端板连接节点设计理论研究

参照欧美钢结构计算手册,并依据端板变形协调条件,推导出端板连接节点螺栓撬力及节点承载力计算公式,并得出了一些有益的结论,从而为端板连接节点的进一步研究和分析提供了理论基础。