工厂加工制作的特殊构造梁柱节点抗震性能试验研究

为研究工业用途的某特种钢结构的抗震性能,选取其中3个特殊构造梁柱节点,即柱强轴方向带悬臂梁段的端板螺栓节点(试件I)、柱强轴方向有梁的弱轴方向异型盖板焊接节点(试件II)、柱强轴方向无梁的弱轴方向异型盖板焊接节点(试件III),制作足尺试件,进行循环荷载作用下的拟静力试验,研究端板连接、空间加载制度以及特殊的构造形式对节点破坏形态、承载力、塑性转角、延性及耗能能力的影响。试验结果表明:3种形式节点试件的梁端最大塑性转角均能达到0.025 rad,位移延性系数大于4.0,累积塑性转角可达最大塑性转角的20~30倍,承载力可达到梁全截面塑性承载力的1.0~1.3倍;试件II的最大层间位移角达到0.035 rad,最终因梁中发生局部屈曲而破坏,而试件I和试件III的最大层间位移角可达0.040 rad,满足美国钢结构抗震设计规范中对特殊抗弯钢框架梁柱节点转动能力的限值要求,破坏形态分别为螺栓拉断、盖板出现延性开裂。研究结果表明,试件II和试件III抗震性能良好,试件I因端板螺栓连接承载力不足,导致其耗能能力较差,因此需从设计上加以改进。     

钢管混凝土梁柱长圆孔变型性高强螺栓节点抗震性能试验研究

设计钢管混凝土梁柱长圆孔变型性高强螺栓节点,上下节点板通过高强螺栓拼接连接钢管混凝土柱与钢筋混凝土梁,并引入长圆形螺栓孔以提高节点的延性变形性能。本文通过两个长圆孔变型性高强螺栓节点试件及两个传统焊接节点试件的低周反复加载试验,对不同连接方式节点在地震作用下的承载力、延性变形能力、耗能能力、滞回性能进行研究与对比。试验结果表明,螺栓节点满足节点承载能力,同时其延性性能好于传统焊接节点,节点的延性变形能力通过螺栓在长圆孔中的滑移有明显提高。与焊接节点相比较,最终两个长圆孔变型性螺栓节点发生延性破坏,较大程度地改善了节点的抗震性能。     

钢框架加强型梁柱节点子结构的抗冲击性能试验研究

设计了采用FEMA 350过焊孔构造的1个普通栓焊连接和2个加强型（盖板和翼缘加强型）栓焊连接的钢框架梁柱节点子结构试件,对试件进行落锤冲击来模拟结构的动态倒塌过程,考察栓焊节点加强方式对钢框架梁柱节点抗冲击性能的影响。通过试验获得节点试件的破坏形态及其冲击作用和位移时程曲线,分析试件冲击作用和位移时程响应规律以及子结构动态转角和耗能变化趋势。试验结果表明：节点试件的主要破坏形态是显著整体弯曲变形和钢梁上翼缘塑性铰截面附近处受压屈曲,采用FEMA 350标准过焊孔构造的节点试件具有良好的抗冲击转动能力,3个试件的极限转角均达到了FEMA 350规范抗震设计的转角限值（普通栓焊节点为θ=0.054 rad、加强型节点为 θ=0.070 rad）要求;改进后的盖板加强型和翼缘加强型节点试件的抗冲击能力均得到显著提高,优于普通栓焊节点。通过分析冲击过程中试件截面内力发展规律可知,由于节点过早破坏,限制了悬链线效应的形成,所有试件最终还处于塑性受弯向悬链线发展阶段。     

方钢管混凝土柱与钢梁框架节点的抗震性能试验研究

为验证方钢管混凝土柱与工形钢梁框架节点的破坏特征和抗震性能,本文进行了A、B两组共6个足尺节点试件的低周反复循环加载试验,其中A组三个试件梁端采用栓-焊连接;B组三个试件梁端为全对接焊接。试验结果表明:6个试件的层间位移延性系数μ≈2.28～3.86,弹性极限层间位移角y≈0.001～0.014,弹塑性极限层间位移角u≈0.0297～0.0424,节点梁柱的相对极限塑性转角θu≈0.0163～0.0343rad,能量耗散系数E≈2.029～2.494;A、B两类节点均有良好的抗震性能,在相同轴压比下A类节点的延性较B类略好一些,而耗能能力B类节点却略大一些,但二者相差不大,均满足结构抗震设计的要求。文章还分析了节点域的剪切变形,给出了改造节点设计的几点建议。     

钢管混凝土梁柱长圆孔高强螺栓节点抗震性能有限元分析

国内某高铁火车站地下地铁站结构,采用钢管混凝土柱和普遍钢筋混凝土梁结构形式.节点拟采用传统的焊接节点和长圆孔变型性高强螺栓节点两种方案.文章通过有限元软件对这两种节点方案在地震作用下的延性变形能力、滞回性能、耗能能力、塑性转角等进行分析与对比.有限元分析结果表明,螺栓节点拥有较好的延性性能和抗震性能.     

矩形钢管柱与H型钢梁单边螺栓连接节点的抗震性能与恢复力模型研究

为研究矩形钢管柱与H型钢梁单边螺栓连接节点抗震性能,对5个单边高强螺栓连接节点试件和1个常规高强螺栓连接节点试件进行了拟静力试验,研究了矩形钢管柱与H型钢梁单边螺栓连接节点破坏模式、滞回曲线、骨架曲线、延性、耗能、刚度退化等抗震性能指标,对比了单边高强螺栓与常规高强螺栓连接节点抗震性能的差异性;分析了节点构造参数对单边高强螺栓连接节点抗震性能的影响,根据节点滞回特性和单边高强螺栓受力特点提出了节点恢复力模型。研究结果表明:节点试件的破坏模式中单边高强螺栓均产生滑移现象;节点试件的滞回曲线捏缩严重,滞回曲线呈反S形,且有明显滑移直线段;节点试件初始转动刚度约为常规高强螺栓连接节点的70%,单边高强螺栓滑移使节点具有很大的转动变形能力,节点试件的极限转角为0.06~0.08 rad;节点的受弯承载力与常规高强螺栓连接节点基本一致,单边高强螺栓能够满足节点承载力设计要求;节点试件的等效黏滞阻尼系数为0.15~0.17,等效耗能系数为1.29~1.77,延性系数为1.62~2.26,其耗能和延性性能均低于常规高强螺栓连接节点;通过设置端板加劲肋可有效提高节点试件的抗震性能,设置内隔板对节点试件的抗震性能提高效果不明显;提出的节点恢复力计算模型与节点试件的试验曲线吻合较好。     

LY315钢材带悬臂梁段拼接梁柱节点抗震性能试验研究

带悬臂梁段拼接梁柱节点是我国GB 50011—2010《建筑抗震设计规范》推荐的节点设计形式之一,为研究LY315钢材带悬臂梁段拼接梁柱节点的抗震性能,开展了高强度螺栓抗滑移系数试验及梁柱节点循环加载试验,试验获得了该类型节点的破坏模式、滞回曲线、骨架曲线及延性系数等,探讨了悬臂梁段长度对该类型节点抗震性能的影响。试验研究结果表明：对于LY315钢材,采用钢丝刷清除浮锈的表面处理方式所得螺栓抗滑移系数为0.29;以此钢材制作的带悬臂梁段拼接梁柱节点试件滞回曲线饱满,具有良好的耗能能力;3个试件在加载终止时转角均超过0.04rad且试件的延性系数均大于4,表明该类型节点具有良好的变形性能及延性;随着悬臂梁段长度的增加,试件的累积耗能能力有所降低,这是螺栓的滑移耗能造成的;随着悬臂梁段长度的增加,节点的承载力则略有提高,而悬臂梁段长度的变化对试件的延性及刚度退化影响不大。     

带十字形预制件的全螺栓连接钢模块节点抗震性能试验研究

提出了一种带十字形预制件的全螺栓连接钢模块节点。为研究该节点的抗震性能,采用不同的梁端、柱端连接方式、梁段削弱形式以及十字形预制件构造形式设计了5个节点试件。对5个节点试件进行了低周往复加载试验,分析了节点的破坏模式和拼接区的滑移情况,获得了节点的滞回曲线、骨架曲线、延性系数、耗能能力、转动能力、刚度退化等抗震性能指标。研究结果表明：节点试件的破坏模式为拼接区拼接板及十字形预制件贯穿隔板的塑性变形及核心区部分焊缝开裂;5个节点试件的滞回曲线较为饱满且为“Z”形,具有较好的耗能能力;5个节点试件的位移延性系数均超过4,塑性转角均超过0.03rad,满足抗震规范要求,具有良好的转动能力和延性;5个节点试件均有明显的刚度退化现象,但下降坡度缓慢;不同的拼接区连接形式和不同的十字形预制件构造对节点抗震性能有一定的影响;不同的梁段削弱形式对节点抗震性能影响不明显。     

方钢管混凝土柱与钢梁全螺栓节点抗震性能试验研究

通过对6个钢管混凝土柱-钢梁全螺栓连接节点及1个栓焊节点的低周反复加载试验,研究了全螺栓连接节点的破坏模式、承载力以及延性性能。试验表明:当试件的弹塑性层间位移角达到规范限值的2.15~3.02倍时,全螺栓连接试件仅在连接板件远端处钢梁翼缘上出现较小的鼓曲变形,变形幅度远小于栓焊节点;全螺栓连接节点具有更大的塑性变形能力、更大的峰值荷载和更长的屈服平台,能够满足抗震规范位移限值要求。试验指出,全螺栓连接节点的各组件在地震作用下都能发挥耗能作用,耗能机制包括连接板和钢梁翼缘间的摩擦耗能、栓杆与孔壁挤压耗能、连接板下的钢梁翼缘塑性变形耗能以及连接板远端处钢梁塑性耗能等。全螺栓连接试件的滞回曲线包括相对平直段和上升段,分别对应连接板与钢梁翼缘的滑动摩擦阶段和螺栓孔与螺杆的接触挤压阶段。试件经过多级位移循环加载后,摩擦力衰减明显,约为屈服荷载的50%;每级位移加载后期,由于螺栓杆与孔壁产生接触作用,试件的承载力相比摩擦滑移阶段明显增大,并且随位移加载幅值的增大而增大,峰值荷载可达到屈服荷载的2~3倍。     

方钢管混凝土柱穿芯螺栓—端板节点抗震性能试验研究

对三个穿芯螺栓-端板连接节点进行了伪静力试验研究,研究了不同轴压比时节点的滞回性能、强度和刚度退化、延性、耗能性能及破坏特征.结果表明,试件的层间位移延性系数为2.38～2.45,弹性及弹塑性层间位移角分别为0.0140～0.0158rad、0.0341～0.0377rad,能量耗散系数为2.567～3.820.所有节点试件均为梁端形成塑性铰而破坏,节点具有较好的强度、刚度、延性和耗能能力.提出了相关的设计及研究建议.     

Evolutionary structural optimization of steel gusset plates

Evolutionary structural optimization is applied to determine the optimum shape of steel gusset plates subjected to axial forces. A number of different gusset plates used in various types of connections is considered for this purpose. The evolutionary structural optimization approach is employed to find the optimum shapes of a gusset plate used in these connections. The first example considers a gusset plate having two holes which are utilized in the connection of double angle carrying a tensile force. Within this example the effect of certain parameters in the evolutionary structural optimization process such as material removal ratio, mesh size and modeling of holes on the final shape is investigated. The gusset plates having three, four and five holes are also designed for optimal shape. Furthermore design examples include two rows of multiple holes as well as staggered holes and connections with multiple members. The final shapes obtained in the single member bolted connections are generally similar to those used in practice. However, they are lighter. Those shapes obtained for the multiple member connections and welded double angle connections are unpredictable. Although the shapes obtained in all the examples are lighter than the ones used in practice, they might be more expensive to produce. It is shown that the evolutionary structural optimization method has a potential in determining the optimum shape of gusset plates.     

Bolted steel slip-critical connections with fillers: I. Performance

This paper reports the results of sixteen experiments of bolted slip-critical connections with fillers. Fifteen of the connections used oversized holes and one connection used standard holes. Such connections with oversized holes are commonly fabricated for use with structures such as long-span trusses, since the use of oversized holes allows erection in-place rather than first assessing fit-up on the ground. Filler plates are used to connect members of different depths or widths. The sixteen experiments reported herein highlight the behavior of bolted steel connections with oversized holes in which fillers are included and are undeveloped, partially developed, or fully developed. Both single-ply and multi-ply fillers are investigated, as are welded developed fillers, and specimens fabricated using either turn-of-the-nut or tension control bolts to pretension the connection. The results augmented with previous literature document the slip and shear strengths of these connections, propose formulas for assessing these strengths for the different conditions investigated, and provide recommendations for design of these types of connections.     

层板胶合木梁柱钢填板-螺栓连接节点横纹受力性能试验研究

为研究层板胶合木梁柱钢填板-螺栓连接节点横纹受力性能，对6组20个足尺节点试件进行抗剪试验，获得了节点的受剪性能指标和特征曲线。结果表明：节点的破坏均表现为木材的横纹劈裂脆性破坏，且第一条贯穿裂缝基本出现在靠近加载侧的螺栓孔处；相比于加载边边距e2，非加载边边距e1对节点的力学性能影响更为显著，非加载边边距e1取30~70mm时节点的屈服荷载和弹性刚度的变化幅值分别达16.6%和60.8%。总体上，试验所得受剪承载力与理论公式计算的相差较大，但相对而言，由van der Put计算公式计算的受剪承载力与试验结果最为接近，且偏于保守。     

Cyclic testing and parametric study of bolted beam-height adjustable steel beam-to-column connections

A kind of bolted beam-height adjustable beam-to-column connections (BHA connections) is proposed for moment-resisting steel frames. It is applicable when the height of beams change in small ranges. A BHA connection is composed of a T-shaped connector, an L-shaped connector with ellipse-type blot holes and bolts. A cyclic test on four full-scaled subassemblies and a series of numerical parametric analyses of BHA connections were conducted to study their mechanical performance. The test results show that the BHA connections with properly stiffened L-shaped connectors possessed good hysteretic properties, stabile secant stiffness and load-carrying capacity degradation and excellent energy dissipation capacity. And the effect of connector slippage and beam web eccentricity was negligible. It can be found in the parametric study that the flange thickness of T-shaped connectors played a pivotal role both in the load-carrying capacity and elastic stiffness of BHA connections, and the elastic stiffness was also affected by the thickness of T-shaped connector webs, L-shaped connector flanges and webs, and column stiffeners. Moreover, the numerical results also demonstrated that the column stiffeners in joint regions could improve the efficiency of load transfer between beams and columns. This kind of connections can be used to assemble steel frames expediently.     

盾构隧道管片衬砌壳-弹簧计算模型研究

针对现有盾构隧道管片衬砌计算模型存在的问题,对管片接头的力学特性进行了分析。认为管片的接头实际应包括管片接缝和对应手孔间的管片部分,采用点弹簧模拟管片接头力学特性实际上是夸大了端部管片的刚度。提出了基于壳-弹簧模式的管片结构的整体环-纵向非连续计算模型,改进了接头的模拟方法。该模型将管片接缝以及对应手孔间管片部分视为一个受力整体,其宽度约为对应手孔之间的弧长,并提出了该接头抗弯刚度的定义方式。由于该模型考虑了管片接头的整体性,计算得到的内力值比梁-弹簧模型计算结果更加准确,且可反映管片结构纵向的受力特征。     

带齿夹板钢木连接节点受力机理

为解决胶合木网壳螺栓连接节点初始刚度低、木梁螺栓孔易发生劈裂的问题,提出一种带齿夹板钢木连接节点。通过试验研究了带齿夹板节点(JD-2)在单调荷载作用下的力学性能和破坏模式,并与同尺寸下不含钢齿的普通夹板节点(JD-1)进行对比分析。为深入研究带齿夹板节点的受力机理,对带齿夹板节点进行有限元模拟。结果表明:JD-1的破坏模式为木梁沿螺栓孔水平连线方向的横纹劈裂破坏,JD-2的破坏模式为夹板屈服破坏; 与JD-1相比,JD-2的初始刚度提高了47.18%,极限承载力提高了31.4%,延性系数提高了19.83%; 钢齿与木梁之间的机械咬合作用可以有效减少木梁螺栓孔初始间隙对节点刚度的不利影响; 在弯矩与剪力联合作用下,荷载通过钢齿及螺栓共同传递给木梁,减少了木梁螺栓孔的应力,因此延缓了木梁螺栓孔的开裂; 随着夹板翼缘厚度的增加,节点的受弯性能呈现增大的趋势; 增加夹板布齿率,木梁螺栓孔受到螺栓挤压应力减小,钢齿阻止夹板与木梁之间的相对滑动能力增强,建议夹板布齿率取0.46%～0.65%。     

高强度钢框架梁柱节点低周疲劳断裂性能试验研究

高强度钢结构节点的低周疲劳断裂性能是影响其抗震性能的关键因素,对于高强度钢结构的抗震设计及其在抗震区的推广应用至关重要。为研究受强震作用高强度钢结构节点的低周疲劳断裂性能,完成了4个高强钢框架栓-焊混接梁柱节点足尺试件的低周疲劳往复加载试验,包括2种不同的焊接孔形式和4种焊接工艺,测得各试件的断裂失效模态及承载性能。基于试验结果,分析了焊接工艺细节及焊接孔形式、钢材强度对高强钢框架梁柱节点断裂性能的影响,研究了这类节点的断裂失效机制。结果表明：当采用有效的构造改进措施,且翼缘焊缝质量得以保证时,高强度钢框架梁柱节点破坏前能承受较大的塑性变形,断裂性能良好。     

Comprehending the ductile behavior of slotted bolted connections

Structural steel special moment frames are designed to resist earthquakes with substantial inelastic energy dissipation. The ductile beam‐to‐column connections become more popular over these years by dissipating the earthquake input energy at beam ends. The paper provides a comprehensive study of a high‐strength slotted bolted connection (SBC). Slotted holes instead of round holes are used for the connection such that frictional sliding could be developed. Experimentally, a standard bolt–weld connection as well as three similar slotted bolted connections were designed and tested. The load‐carrying capacities, the ductile deformations, the energy dissipation capacities, and the hysteretic characteristics of the specimens were presented. The overall performance of the steel connections by replacing the circular holes with slotted holes is evaluated, and the design recommendations of the flange gusset plate with slotted holes are provided. Numerically, the nonlinear SBC behavior was simulated and calibrated against the experimental results. The SBC effectiveness as well as the parametrical influences have been presented in details. Results show that the friction slippage behaviors of the specimens with slotted holes provide better ductility, higher plastic deformation capacity, and increased load‐resisting capacities near the ultimate strength.     

钢骨混凝土柱框架节点的试验研究

本文研究了在钢管上开孔对配有圆钢管的钢骨混凝土柱-钢筋混凝土梁组合框架节点受力性能的影响。介绍了三种节点承受低周反复荷载的试验,第一种是不开孔的,第二种是开穿筋小圆孔的,第三种是开矩形大孔的。试验结果表明,开穿筋小圆孔的节点受力性能最好。主要原因是穿过圆钢管的梁主筋与钢管内的混凝土有很好的粘结;在钢管的小孔处形成了钢筋混凝土抗剪销钉,小圆孔也使得钢管内外的混凝土得以沟通;同时钢管参加受剪的主要部位位于节点高度的中部,故在节点上下边缘处开小圆孔对节点受剪性能影响不大。本文研究成果已用于南京新世界大厦,并对研究其他的组合框架节点有参考价值。     

The seismic performance of new detailing for RCS connections

Over the past few decades considerable experimental and numerical studies have been conducted on the Reinforced Concrete columns to Steel beams (RCS) connections. Most of those researches have focused on studying the joint failure modes and ultimate joint strength of specimens utilizing strong beams and columns with weak joints. In this paper, two interior RCS connections were designed based on the Strong Column–Weak Beam (SCWB) criterion. Both specimens were tested under quasi-static reversed cyclic loading. The tested specimens were modeled by a finite element method, which verified with experimental results. Several models with different joint details were investigated using the verified FEM. Lateral load–story drift response, vertical bearing stresses, joint shear forces, shear strains at the joints, and axial stresses of the joint stirrups were studied in those models. The results indicated that the performance of models directly depends on joint detailing, effectiveness of shear keys, and the amount of confinement provided for a joint region.