薄壁方钢管混凝土梁柱节点抗震性能试验研究

以轴压力为主要参数,对两种形式共6个薄壁方钢管混凝土柱-空心方钢管梁节点进行滞回性能的试验研究。通过试验,研究试件的破坏模式、滞回特性、延性及耗能能力等重要抗震性能指标。结果表明:直接焊接节点破坏主要由梁与柱的焊接处断裂引起,螺栓贯穿式连接节点主要发生梁与端板的焊接处断裂和端板与柱的连接焊缝拉裂;轴力对直接焊接节点的抗震性能指标影响较大,而对螺栓贯穿连接节点的影响不是很明显;螺栓贯穿式连接节点的初始刚度和极限承载力都比直接焊接节点要弱,但其屈服平台相对较长,达到极限承载力后其承载能力下降也相对缓慢,延性较好,耗能能力较强;螺栓贯穿式连接节点在破坏时由焊接端板构成第二道防线,对结构抗震更为有利。     

单边高强螺栓连接方套方中空夹层钢管混凝土柱组合节点抗震性能试验研究

为了深入研究单边高强螺栓连接中空夹层钢管混凝土柱组合节点的抗震性能和破坏机理,对4个方套方中空夹层钢管混凝土柱与钢-混凝土组合梁单边高强螺栓端板连接节点进行了低周反复加载试验,以端板形式和柱截面空心率为主要试验参数,考察了节点破坏模式和组合楼板裂缝分布规律,研究节点滞回曲线、连接弯矩-转角关系、刚度和承载力退化、延性和...     

方套方中空夹层钢管混凝土柱单边螺栓连接节点#br# 拟动力试验分析

为揭示中空夹层钢管混凝土柱单边螺栓连接在地震作用下的动力特性和破坏模式,文章选取典型的中柱节点作为试验模型,进行方套方中空夹层钢管混凝土柱单边螺栓端板连接节点拟动力试验。研究柱截面空心率、端板形式以及采用可拆卸组合楼板对节点动力性能的影响。获得节点在各工况下的动力特性和破坏模式,分析构件最大位移时程曲线、最大加速度时程曲线、柱顶水平荷载-水平位移滞回曲线,获得阻尼比、刚度退化和累积滞回耗能等抗震性能指标的变化规律。试验结果表明,方套方中空夹层钢管混凝土柱单边螺栓端板连接节点具有优越的抗震性能和良好的延性,可以在高烈度地区的多高层装配式钢结构建筑中应用和推广。     

装配式钢管混凝土组合框架的抗震性能试验研究

圆形或方形钢管混凝土柱与钢梁通过单边高强螺栓和适宜端板连接组成框架,通过钢筋桁架混凝土组合楼板形成了新型装配式组合框架。为了解装配式钢管混凝土组合框架在地震作用下的抗震性能和受力机理,进行了2榀两层单跨钢管混凝土柱与钢-混凝土组合梁通过单边高强度螺栓和平齐或外伸端板连接形成的组合框架的水平低周反复荷载试验,研究了柱截面形式和端板连接类型对组合框架破坏形式和抗震性能的影响。详细地观察了此类组合框架在水平低周反复荷载作用下的受力全过程和楼板裂缝发展规律,得到了此类结构的滞回曲线、骨架曲线、刚度退化规律、延性、耗能能力等抗震性能指标。试验结果表明,单边螺栓端板连接装配式钢管混凝土组合框架结构具有良好的滞回性能和耗能能力,延性系数μ为2.13~4.28,能量耗散系数E为0.652~0.90。在柱截面含钢率相同条件下,圆钢管混凝土组合框架的承载力小于方钢管混凝土组合框架,其延性、耗能性能优于方钢管混凝土组合框架。研究成果将为我国装配式钢管混凝土组合框架设计理论与应用提供科学依据。     

两层钢管混凝土柱与组合梁单边螺栓端板连接框架拟动力试验研究

为揭示半刚性钢管混凝土组合框架在地震作用下的动力特性和破坏形式,对2榀两层单跨钢管混凝土柱与 组合梁单边螺栓端板连接组合框架进行拟动力试验研究。该试件的梁柱连接节点形式为平齐端板或外伸端板连接 ,组合楼板采用钢筋桁架楼承板,试验影响参数为柱截面类型和端板类型。研究了El-Centro地震波作用下结构 的加速度反应和位移响应,分析了滞回性能、刚度、延性和耗能能力等,评价了梁柱半刚性连接和楼板组合效应 对组合框架结构整体性能的影响。试验表明：半刚性钢管混凝土组合框架具有良好的抗震性能和耗能特性。在柱 截面宽度和含钢率相同条件下,采用单边高强螺栓端板连接方式,圆钢管混凝土组合框架的最大位移响应和累积 耗能比方钢管混凝土组合框架大;方钢管混凝土组合框架的水平承载力和初始刚度优于圆钢管混凝土组合框架。 研究成果将为我国装配式组合结构设计理论与应用提供科学依据。     

冷弯薄壁方钢管混凝土梁柱节点抗震性能试验研究北大核心CSCD

冷弯薄壁型钢结构房屋中杆件壁板较薄,梁柱节点连接区域常发生柱板件被拉裂现象。向薄壁柱内灌入低强度混凝土,可有效提高梁柱节点抵抗外荷载的能力。开展4种类型共8个节点在不同轴压比下的低周往复加载试验,探讨节点抗震性能。结果表明:普通空钢管柱焊接节点破坏前所经历的循环次数较少,节点域部位焊缝及焊缝附近板件发生断裂;加腋节点极限承载力比普通焊接节点提高很多,耗能能力较强,破坏时加腋端梁截面局部屈曲,其承载力比螺栓贯穿式节点承载力高;钢管混凝土柱直接焊接节点在一定程度上抑制了节点域柱板件断裂,螺栓贯穿式节点梁端板件发生断裂和梁与端板连接的焊缝也被拉裂;轴压比对空钢管柱节点的抗震性能影响较大,但对钢管混凝土柱节点影响较小。     

钢管混凝土柱-钢梁边柱外加强环螺栓连接节点抗震性能

传统钢管混凝土柱-钢梁外加强环焊接节点,由于环板上应力集中现象严重,环板与钢梁连接处易出现撕裂破坏.为此,提出了一种装配式螺栓连接节点形式,即将钢梁伸入上下外环板之间,钢梁翼缘与斜直边环板采用高强度螺栓连接,改变节点连接处传力路径,改善环板受力性能.进行了3个边柱节点拟静力加载试验,研究H型钢梁截面高度、外环板与H型钢...     

国际期刊导读

1循环荷载下钢管混凝土柱与钢梁连接节点的试验研究摘要:在循环位移控制荷载下,对4个内部连接钢梁和钢管混凝土(CFT)柱的1/2尺寸试件模型进行试验。考虑方钢管柱和圆钢管柱有两种不同的连接方式:1)由工厂焊接而成的平型和弧形外伸型端板被螺栓固定在有钢条整体贯通的钢管混凝土柱上;2)梁贯通式连接则是在梁柱间不进行任何焊接的情     

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。     

钢管混凝土柱-钢梁单边高强螺栓端板连接框架的拟静力试验研究

为获悉半刚性钢管混凝土框架结构在地震作用下的抗震性能和破坏机理,进行2榀两层单跨钢管混凝土柱与钢梁单边高强螺栓端板连接框架试件的拟静力试验,包括1个圆形和1个方形钢管混凝土框架。研究柱截面类型和端板类型对框架破坏形式和抗震性能的影响。详细地观察了框架在低周反复荷载作用下的受力全过程和破坏特征,分析此类结构的滞回曲线、骨架曲线、强度和刚度退化规律、耗能能力等抗震性能指标,并结合现有规范评价结构的延性。试验结果表明,此类半刚性连接钢管混凝土框架结构具有良好的滞回性能和耗能能力,其延性系数μ=2.41-3.75,能量耗散系数E=0.823-0.955|在柱截面含钢率相同条件下,方钢管混凝土框架试件的极限承载力和耗能能量均高于圆钢管混凝土框架试件|梁柱节点采用单边高强螺栓端板连接具有典型的半刚性特征,连接可靠和耗能效果好。研究成果将为我国装配式组合结构设计理论与应用提供科学依据。     

Seismic behavior of exterior connections with steel beams bolted to CFT columns

In order to improve the constructability and meanwhile ensure satisfactory seismic behavior, an innovative type of connection for concrete filled circular steel tube (CFT) column-to-steel beam composite structures was conceived and studied. The proposed connection details are characterized by an extended endplate that is welded to a steel beam in factory and then bolted to a CFT column using high-strength steel rods in the field. An experimental investigation on seismic behavior of the proposed bolted endplate connection and evaluation of the effect of concrete floor slabs and reduced beam sections was conducted by testing three full scale joint models. The experimental results indicated that the presence of floor slabs contributed to the strength of joints significantly and reduced beam sections were effective in moving the buckling zone away from the welds. Analytical models for the bolted endplate connections were also constructed using OPENSEES1.7.3 to simulate the experimental results.     

Seismic behavior of bolted beam-to-column connections for concrete filled steel tube

Concrete-filled steel tubes (CFT) have the advantage of high strength, high stiffness and being constructed quickly. However, because the behavior of the beam-to-column connection for CFT is complicated and its design has not been sufficiently verified, their use has been limited.In this paper, a new design of bolted beam-to-column connections for CFT is proposed. A mechanical model is established in order to derive theoretical equations for calculating the stiffness, the yielding shear strength and the ultimate shear strength of the panel zone. Also, a series of cyclic loading experiments have been conducted. The experimental results and theoretical results are very close, which demonstrates that the bolted connections have superior seismic resistance in stiffness, strength, ductility and energy dissipation mechanisms. From the laboratory studies, even though the story angular drift reaches 7% and the plastic angular displacement reaches 5%, the structure still stands. Those results indicate that the seismic resistance exceeds those specified in Taiwan and the US.     

圆形钢管混凝土柱的基础连接件

钢管混凝土柱促进了经济且快速的建设方式。两者的组合增大了结构钢和混凝土的强度和刚度,使用钢管作为模板和核心混凝土的约束减少了工作量。钢管混凝土柱为混凝土和钢材提供了一个共生关系来缓和其不良的失效模式,激发了各种材料的最优性能(混凝土和钢材)。综合作用下,混凝土抗压强度和刚度增大,延缓和抑制了钢管的局部屈曲,并提升其延展性和抗力。矩形钢管混凝土柱与圆形钢管混凝土柱都被应用于实际建设生产中,但由于圆形钢管混凝土柱可以提供更强的混凝土约束和综合作用而拥有更好的性能。对于圆形钢管混凝土柱来说,其缺少可靠的、有延展性的连接件。对这方面的研究调查进行介绍,包括关于圆形钢管混凝土柱柱脚或钢筋混凝土地基柱的简便经济的连接件的开发设计过程,并介绍和评价了桥梁结构中的桩帽与宽桩梁。这种连接件不需要销子和内在的加固就能将钢管与基脚或桩梁相连接。试验分析研究和评估了这种连接件的非弹性抗震性能,并确立了设计标准。将1个装配这种连接件的钢管混凝土柱的抗震性能与传统的钢筋混凝土柱相比较。结果显示,此种连接件进一步增强了组合柱的承载力。这种形式在地震荷载下能提供极佳的延展性和非弹性变形能力,甚至在大侧移情况下也能减轻损害。     

Hysteresis behavior of concrete filled square steel tube column-to-beam partially restrained composite connections

This study presents the development of an improved detail for a Concrete Filled Steel Tube (CFT) square column-to-beam partially restrained composite connection (PR-CC) and the evaluation of its hysteresis behavior under cyclic loading. The detail of the connection was designed to prevent brittle failure at the bottom of the connection due to the composite effect and to simplify its fabrication process. The suggested connection is a welded type of bottom beam flange connection and the existing PR-CC is a bolted type with a seat-angle. To evaluate their hysteresis behavior, specimens were fabricated at full scale and tested under cyclic loading. Results revealed that the suggested type fractured at the welding zone without a drop in capacity due to the anchors inside the steel tube, and reached over 0.04 radian of the plastic rotational angle. The stiffness of the suggested type was about 10% greater than the existing type because the bolted connection allowed more deformation than the welded connection. Both connections were classified as Semi-rigid connections by stiffness analysis according to Eurocode3. The suggested type can be classified as a partially restrained connection overall under cyclic loading because it reached more than 0.03 rad of an inelastic rotation angle 80% capacity of the maximum moment capacity. This type was evaluated to exhibit equal or more ductility than the existing type. As a result, it is concluded that the welded bottom beam flange connection type can be used in practice for the CFT column-beam connection instead of the existing bolt connection using a seat-angle.     

带楼板的钢梁和CFT柱抗弯连接的抗震分析

对4个带楼板的钢管混凝土柱连接进行抗震性能分析,包括2个内部和2个外部节点。研究目的主要是对台湾地区广泛采用的钢梁组合楼板的性能进行分析。其次对梁末端楔形翼缘或者较大剪切键等连接处的抗震性能也进行了研究,以避免如Northridge地震后出现的那种不可预料的脆性破坏导致的梁翼缘焊缝完全熔透。     

可更换钢连梁抗震性能试验研究

通过拟静力试验,研究由跨中部消能梁段和两端非消能梁段组成的可更换钢连梁的抗震性能和震后可更换能力。试验共包括4个连梁试件,采用4种不同的消能梁段与非消能梁段连接方式,分别为端板-抗剪键连接、拼接板连接、腹板-螺栓连接、腹板-结构胶连接。试验结果表明：采用端板-抗剪键连接时,连梁的塑性变形和损伤集中在消能梁段,连梁的极限塑性转角可达0.06 rad,具有稳定的滞回耗能能力;采用拼接板连接或腹板-螺栓连接时,消能梁段剪切屈服,连接处摩擦型高强螺栓有不同程度的滑移,连梁的极限塑性转角也可达0.06 rad;采用腹板-结构胶连接时,连接处结构胶开裂导致连梁脆性破坏。在连梁转角为0.02 rad加载后对消能梁段进行更换,采用端板-抗剪键连接的试件更换时间最短,而腹板-螺栓连接的试件能在更大的残余转角时更换。此外,消能梁段在较大塑性剪切变形时伴有轴向变形,导致连梁试件承受较大轴力,连梁的轴力影响需要进一步研究。     

Combination of mechanical and informational modeling to predict hysteresis behavior of I beam‐to‐CFT column connection

The behavior of beam‐to‐column connections is significantly complicated because it depends on the material, nonlinear relationship between different members, and contact of connecting elements. Their hysteretic response exhibits highly inelastic characteristics and continuous variation in stiffness, strength, and ductility. Therefore, accurate hysteretic models of bolted connections are essential to accurate seismic assessment and design. Composed (Hybrid) modeling approach is presented to represent the complex hysteretic behavior of I beam‐to‐concrete‐filled‐tube (CFT) column bolted connection. For the purpose in this study, experimental evaluation of I beam‐to‐CFT column connection with bolted end‐plate under cyclic loading is done. It must be mentioned to make the connection easily applicable practically and also prepare the column flanges continuity, a connection with the bolts penetrated into the CFT column are used since using the stiffeners in hollow sections is not easily applicable. In the composed mechanical–informational modeling framework, the conventional mechanical model is complemented by information‐based model components. Finally, moment–rotation curves of composed model have been compared with experimental results. Comparison showed that the composed model has a good agreement with experimental results. A newly designed specimen for validation purpose of the composed modeling was made and experimented. Composed model was well applied to predict the behavior of new connections. The presented results show that the composed model has a good ability to predict of hysteretic behavior.     

带悬臂梁段拼接的梁柱连接循环荷载试验研究

为了检验带悬臂梁段拼接的梁柱连接抗震性能,对4个试件进行了循环加载试验。试验侧重于对拼接节点的研究,采用10.9级高强螺栓摩擦型连接,翼缘和腹板全部拼接。试验结果表明:螺栓拼接节点的延性远好于梁柱焊缝连接;较弱的拼接节点产生较大的塑性变形;接触面的滑移摩擦、螺栓与孔壁的挤压和翼缘拼接板的屈曲都使连接具有良好的耗能能力;但滑移伴随有剧烈的响声,会使人产生心理恐慌。根据试验结果提出了设计建议:尽量将拼接设计得弱些,可以提高梁柱连接的转动能力,减少地震作用向梁柱连接焊缝的输入,延缓焊缝的脆性破坏。     

Seismic design of reduced beam section steel moment connections with bolted web attachment

Recent test results on reduced beam section (RBS) steel moment connections showed that specimens with a bolted web connection tend to perform poorly due to premature brittle fracture of the beam flange at the weld access hole. The measured strain data appeared to indicate that a higher incidence of base metal fracture in bolted web specimens is related, at least in part, to the increased demand on the beam flanges due to the web bolt slippage and the actual load transfer mechanism which is significantly different from that usually assumed in connection design. In this paper, the practice of providing web bolts uniformly along the beam depth was brought into question. A new seismic design procedure, which is more consistent with the actual load path identified from analytical and experimental studies, is proposed. A pilot test specimen designed by following the proposed procedure exhibited sufficient cyclic connection rotation capacity without fracture.     

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。