Self‐centering steel–timber hybrid shear wall with slip friction dampers: Theoretical analysis and experimental investigation

An innovative self‐centering steel–timber hybrid shear wall (SC‐STHSW) system is proposed as a promising structural solution for earthquake‐resilient buildings. The SC‐STHSW is composed of posttensioned (PT) steel rocking frame and infill light‐frame wood shear wall. The PT steel frame provides self‐centering capability, whereas the infill wood shear wall improves the lateral stiffness and the load resistance. Meanwhile, friction dampers are assembled into the connections between the steel frame and the infill wall to provide energy dissipation. Theoretical analysis and cyclic loading test were conducted to comprehend the load‐resisting behavior of the proposed SC‐STHSW system, and closed‐form solutions of the moment, shear, and axial force distribution along the length of the steel beam were formulated. Moreover, a nonlinear finite element model was developed, and the model was further used to verify the derived theoretical formulas. Results showed that the SC‐STHSW system was able to undergo large interstory drift without the development of plastic zones in the steel frame members, which resulted in very small residual deformation. The presented experimental and numerical results aim to provide a practical structural solution for high‐performance earthquake‐resilient buildings.     

Load-sharing mechanism in timber-steel hybrid shear wall systems

The lateral performance of timber-steel hybrid shear wall systems with regard to the interaction between the steel frame and the infill wood shear wall was investigated in this paper. A numerical model for the timber-steel hybrid shear wall system was developed and verified against test results. Design parameters, such as the lateral infill-to-frame stiffness ratio and the arrangements of wood-steel bolted connections were studied using the numerical model. Some design recommendations were also proposed based on the parametric analysis. In the hybrid shear wall system, the infill wood wall was found to resist a major part of the lateral load within relatively small wall drifts, and then the steel frame provided more lateral resistance. Under seismic loads, the infill wood wall could significantly reduce the inter-story drift of the hybrid system, and a complementary effect between the infill wood wall and the steel frame was observed through different lateral load resisting mechanisms, which provided robustness to the hybrid shear wall systems.     

木框架-夹板剪力墙组合结构抗侧力性能试验研究

为研究木框架-夹板剪力墙组合结构的抗侧力性能,对5榀木框架-夹板剪力墙试件、2榀纯框架试件和2片夹板剪力墙试件开展了低周反复加载试验,对比分析试件在往复荷载作用下的破坏机理、抗侧刚度、极限承载力、延性、刚度退化规律和耗能能力。研究结果表明,木框架-夹板剪力墙组合结构的抗侧力性能主要取决于内填夹板剪力墙的性能,其最终的破坏模式表现为共用墙骨柱因钉连接的失效而脱落。外侧梁柱框架对内填夹板剪力墙的约束作用能显著减小端部墙骨柱的上拔,可取消抗倾覆连接件的设置。木框架-夹板剪力墙组合结构的抗侧刚度和极限承载力约为木框架-常规轻木剪力墙组合结构的两倍,且在大变形情况下仍能持有70%峰值荷载的承载能力,有利于避免罕遇地震下的倾覆倒塌。     

自复位钢木混合剪力墙：抗侧力性能试验研究与自复位机理参数分析

该文提出一种新型自复位钢木混合剪力墙体系,其由自复位钢框架、轻型木剪力墙及滑动摩擦型阻尼器组成。通过往复加载试验研究了自复位钢木混合剪力墙体系的抗侧力性能、破坏模式、剪力在钢框架与木剪力墙中的分配规律以及钢绞线内力变化规律。在此基础上,基于OpenSEES平台建立了自复位钢木混合剪力墙的数值模型,并通过试验数据验证了模型的准确性。利用该数值模型进行体系关键参数分析,研究了不同参数设置下自复位钢木混合剪力墙的自复位性能。分析参数选为阻尼器激发力水平及体系初始预应力水平。结果表明：自复位钢木混合剪力墙体系的滞回曲线呈“旗帜型”,自复位性能良好,大位移下阻尼器锁定可带来体系强度与刚度的二次提升;试验中,阻尼器长圆孔设置较长可有效减轻木剪力墙中损伤。参数分析结果显示,阻尼器激发力水平的提高会降低体系的自复位性能,相同阻尼器激发力水平下,体系初始预应力水平的提高不会持续提高体系的自复位性能;根据参数分析结果,给出了自复位钢木混合剪力墙体系中阻尼器激发力与体系初始预应力水平选取的建议公式。     

砌体填充墙RC框架结构平面内抗震性能有限元模拟

砌体填充墙RC框架结构是我国建筑结构中普遍采用的结构形式,历次地震震害表明填充墙的刚度效应和约束效应改变了主体结构的传力机理,导致整体结构的严重破坏。为了分析其砌体填充墙RC框架侧向承载力和刚度,研究砌体填充墙与RC框架之间的相互协同工作机理和砌体填充墙的开裂模式以及砂浆层的滑移,该文利用三维实体单元和基于表面的粘性接触面模型和摩擦原理,建立一种能够较好地模拟其平面内抗震性能的分离式有限元模型。对一个已有试验分别建立普通有限元模型和分离式有限元模型,二者的分析结果与试验结果的对比表明,分离式有限元模拟方法可以更加准确地预测砌体填充墙RC框架结构的侧向承载力和刚度,并且可以有效地模拟出砌体填充墙的开裂模式,通过塑性应变可以判断出RC构件的失效。     

Analyses on mechanical performance of innovative composite shear wall systems

钢板-混凝土组合剪力墙由钢框架、内嵌钢板及一侧通过螺栓与之连接的混凝土板组成,其中传统组合剪力墙中混凝土板四边与钢框架直接接触,而改进组合剪力墙中二者之间有一定间距,以避免其在结构侧移较小时发生接触。采用ABAQUS有限元软件分别建立了组合剪力墙的精细有限元模型,研究了其受力性能以及板框相互作用全过程,分析了钢板高厚比对组合剪力墙整体承载力、抗侧刚度以及板框剪力分配等的影响。研究表明：组合剪力墙中混凝土板有效抑制钢板弹性屈曲,钢板主要以剪切屈服承载,对框架柱的附加弯矩较钢板剪力墙明显降低;相比钢板剪力墙,传统组合剪力墙承载力提高25%,抗侧刚度提高10%,混凝土板承载近30%;改进组合剪力墙承载力提高10%,抗侧刚度提高5%,混凝土板基本不承担剪力;随着钢板高厚比的减小,组合剪力墙的承载力与抗侧刚度提高,但两类组合剪力墙之间的差别变小;钢板承载比例不断增大,当钢板过厚时需要防止底层框架过早屈服。     

钢框架-轻木剪力墙混合结构抗震性能振动台试验研究

为研究钢框架-轻木剪力墙混合结构的抗震性能,设计了缩尺比为2/3的钢木混合结构模型,并对其进行了振动台试验。试验中选取汶川、Canterbury、El Centro和Kobe共4条地震波,并考虑多遇、设防和罕遇3个地震水准,相应的地震加速度峰值分别为0.14g、0.40g和0.80g。通过振动台试验获得了钢木混合结构的地震响应和破坏模式。结果表明：钢木混合结构在多遇地震作用下最大层间位移角为0.15%,罕遇地震作用下最大层间位移角为0.85%,均能满足规范对结构变形的要求;在试验过程中,结构的钢框架部分和钢木连接没有出现损伤,其主要破坏模式表现为轻木剪力墙面板钉节点的破坏,破坏部位主要位于墙体覆面板的边缘;多遇地震作用下,轻木剪力墙承担了结构地震剪力的55.1%以上,有效地提高了结构抗侧承载力;随着输入地震加速度峰值的增大,剪力墙刚度逐渐退化,其分担的地震剪力有所降低,但即使在罕遇地震作用下,轻木剪力墙分担剪力的比例仍能达到39.9%以上。     

Seismic behavior analysis for composite structures of steel frame‐reinforced concrete infill wall

The composite structure of steel frame–reinforced concrete infill wall (CSRC) combines the advantages of steel frames and reinforced concrete shear walls. Reinforced concrete infill walls increase the lateral stiffness of steel frames and reduce seismic demands on steel frames thus providing opportunities to use partially restrained connections. In order to study seismic behavior and load transfer mechanism of CSRC, a two‐story one‐bay specimen was tested under cyclic loads. With that, the main characters such as, strength, stiffness, ductility, energy dissipation, load distribution, performance of steel frames, partially restrained connections and studs, are analyzed and evaluated. The experimental results show that the structure has adequate strength redundancy and sufficient lateral stiffness. The CSRC system has good ductility and energy dissipation capability. Partially restrained connections could enhance ductility and avoid abrupt decreases in strength and stiffness after the failure of infill walls. The composite interaction is ensured by headed studs, which have failed because of low‐cycle fatigue. Steel frames bear 80%–100% of overturning moments, and the remainder is undertaken by infill walls; steel frames and infill walls resisted 10%–20% and 80%–90% of lateral loads, respectively. Furthermore, relevant design recommendations are presented. Copyright © 2011 John Wiley & Sons, Ltd.     

The wall–frame and the steel–concrete interactions in composite shear walls

The nonlinear pushover analyses of 24 composite steel plate shear walls (CSPSWs), 24 corresponding steel plate shear walls (SPSWs), and 24 corresponding frames are conducted. CSPSWs have different aspect ratios and infill steel plate thicknesses. The study aims to understand the wall–frame and steel–concrete interactions. The infill steel plate thickness and aspect ratio of CSPSW are the main parameters of the study. In CSPSWs, the percentage of absorbed shear forces by the infill composite wall is always greater than the infill plate of its corresponding SPSW. The percentage of shear in the composite wall is constant at the initial stage of loading up to a drift of 0.15–0.2%. By increasing the drift, the shear yielding of steel plate leads to a reduction of the shear force absorption. The reduction continues until the bulk of shear stiffness of CSPSW is provided by the frame. At the beginning of lateral loading, steel–concrete interactions increase until shear yield of steel plate. Following this stage, a sudden decrease takes place in shear force absorption of reinforced concrete (RC) panel. The reason is that, at the lower drifts, the steel plate has a tendency for elastic buckling, which is prevented by the RC panel. Finally, the shear force absorption remains approximately constant in the RC panel.     

内嵌CCA板填充墙对钢框架结构受力性能的影响

为了研究蒸压无石棉纤维素纤维水泥板(CCA板)填充墙对钢框架结构受力性能的影响,对纯框架和带CCA板填充墙钢框架进行了低周往复加载试验,并利用有限元软件ABAQUS进行了模拟分析。根据试验及有限元模拟结果对带CCA板填充墙钢框架的承载能力、抗侧刚度和耗能能力等抗震性能指标进行了分析。结果表明:在低周往复荷载作用下,CCA板填充墙提高了钢框架结构的承载能力、抗侧刚度;CCA板填充墙参与了钢框架结构的滞回耗能,带CCA板填充墙钢框架的累积耗能能力明显优于纯框架;与纯框架相比,带CCA板填充墙钢框架的初始刚度有所提高;当位移角达到某一限值时,CCA板填充墙的损坏会引起钢框架结构的刚度发生突变,钢框架结构非弹性设计不应考虑CCA板填充墙对钢框架结构刚度的提高作用;所得结论可为带CCA板填充墙钢框架的工程应用提供参考。     

Experimental Study on Low Cyclic Loading Tests of Steel Plate Shear Walls with Multilayer Slits

A new type of earthquake-resisting element that consists of a steel plate shear wall with slits is introduced. The infill steel plate is divided into a series of vertical flexural links with vertical links. The steel plate shear walls absorb energy by means of in-plane bending deformation of the flexural links and the energy dissipation capacity of the plastic hinges formed at both ends of the flexural links when under lateral loads. In this paper, finite element analysis and experimental studies at low cyclic loadings were conducted on specimens with steel plate shear walls with multilayer slits. The effects caused by varied slit pattern in terms of slit design parameters on lateral stiffness, ultimate bearing capacity and hysteretic behavior of the shear walls were analyzed. Results showed that the failure mode of steel plate shear walls with a single-layer slit was more likely to be out-of-plane buckling of the flexural links. As a result, the lateral stiffness and the ultimate bearing capacity were relatively lower when the precondition of the total height of the vertical slits remained the same. Differently, the failure mode of steel plate shear walls with multilayer slits was prone to global buckling of the infill steel plates; more obvious tensile fields provided evidence to the fact of higher lateral stiffness and excellent ultimate bearing capacity. It was also concluded that multilayer specimens exhibited better energy dissipation capacity compared with single-layer plate shear walls.     

半刚性框架-大高宽比钢板剪力墙抗震性能研究

在半刚性框架-大高宽比钢板剪力墙体系中,半刚性框架和内填钢板均具有很好的延性和耗能性能,两者协同工作进行抗侧以防止结构在地震作用下破坏。为深入研究半刚性框架-大高宽比钢板剪力墙的力学性能,采用ANSYS有限元分析软件对结构进行数值分析,并考察框架节点形式,内填钢板高宽比、高厚比,柱轴压比和肋板刚度比等一系列参数对结构滞回性能的影响。根据内填钢板中心点在循环荷载作用下的面外变形,研究半刚性框架-大高宽比钢板剪力墙的屈曲性能和受力机理。     

三类钢板剪力墙结构试验研究

防屈曲钢板剪力墙已被试验证明是优秀的抗侧耗能构件,但墙板嵌入受弯框架时,二者之间的相互作用尚需进一步研究。为此进行了两层单跨钢框架内嵌防屈曲钢板剪力墙的试验研究,作为比较同时进行了两层单跨钢框架内嵌非加劲钢板剪力墙与两层单跨钢框架内嵌组合钢板剪力墙结构的试验研究。在试验的基础上,对试件进行有限元分析,比较了三类钢板剪力墙之间的性能差异。研究表明,防屈曲钢板剪力墙能够消除无加劲钢板剪力墙在水平荷载下产生的巨大屈曲噪声,具有较大的初始刚度与承载力,拥有良好的延性与滞回耗能性能,而且由于其屈服先于屈曲发生,对周边框架产生的附加弯矩很小;组合钢板剪力墙的性能与防屈曲钢板剪力墙相似,但由于后期外包的混凝土发生脱离,内嵌钢板剪力墙会产生拉力带,不仅对框架产生不利影响,而且自身承载力、刚度与耗能能力均有不同程度的退化。图32表1参12     

足尺水泥聚苯模壳格构式混凝土填充墙钢筋混凝土框架抗震性能试验研究

为研究水泥聚苯模壳(EPSC)格构式混凝土填充墙钢筋混凝土(RC)框架的抗震性能,对一足尺单层EPSC格构式混凝土填充墙RC框架模型进行了振动台试验。试验中考虑了墙体开洞及墙体与RC框架的连接方式,研究了不同强度地震动作用下模型结构的动力特性、加速度反应、位移反应、层间剪力和动应变反应。研究结果表明：连续强震动作用下EPSC裂缝数量较多,部分格构柱水平开裂,而RC框架未发现损伤,EPSC格构式混凝土填充墙RC框架具有良好的抗震性能;模型最大层间位移角仅为1/513,格构式混凝土墙体的存在极大增强了RC框架的抗侧刚度;墙体与RC框架设置不同间距、长度的拉结筋均能提高墙体的平面外稳定性能,可控制墙体与框架协同工作。     

开洞加劲钢板剪力墙的抗侧承载力分析

为研究墙板开洞对加劲钢板剪力墙抗侧承载力的影响,首先建立了梁 壳混合弹塑性有限元单层墙板模型,研究了极限状态下影响开洞加劲墙板受剪承载力的关键因素。在此基础上,通过大量有限元计算和参数分析,提出了用于计算开洞加劲墙板受剪承载力折减率的简化计算式,并与有限元计算结果进行对比,精度满足要求。以3个加劲钢板剪力墙试件的低周往复荷载试验研究为基础,建立了精细有限元分析模型,有限元分析结果与试验结果吻合良好,证明了模型的合理性和准确性。提出了加劲钢板剪力墙结构抗侧承载力的理论模型和计算公式,理论计算结果与有限元分析结果吻合良好。     

RC框架填充墙的计算模型探讨

为了使建筑结构设计过程中,合理考虑填充墙的作用,总结并探讨了RC框架填充墙的计算模型。砌体填充墙计算模型主要包括斜压杆模型、匀质化连续有限元模型及精细化有限元模型。通过分析及实例验证表明,填充墙采用匀质化连续模型,墙-框截面采用界面单元模型计算,能较好地评价RC填充墙框架的性能,应用于实际工程是可行的。     

Stiffness analysis of concrete filled steel plate composite coupling beams

联肢剪力墙弹性阶段的内力分布、抗侧刚度等工作性能主要受墙肢与连梁刚度的影响。为了准确分析外包钢板-混凝土联肢组合剪力墙的受力性能,对外包钢板-混凝土组合连梁的刚度进行了分析。基于钢板与混凝土无相对变形和忽略混凝土抗拉强度的基本假定,建立了组合连梁钢与混凝土无滑移的截面内力与变形之间的关系,并推导了截面刚度的计算公式。对于常用工程设计参数范围内的组合连梁,考虑滑移后得到的抗侧刚度相比无滑移情况减小了10%~24%。通过对无滑移组合连梁刚度公式中的混凝土部分贡献的折减(折减系数为0.5),得到了无特殊界面构造的外包钢板 混凝土组合连梁的刚度计算公式。通过与有限元分析和试验结果的对比,验证了公式的准确性。     

Effect of column stiffness on drift concentration in steel plate shear walls

Steel plate shear walls (SPSWs) are a lateral force resisting system consisting of thin infill steel plates surrounded by boundary frame members. Hysteretic energy dissipation and lateral force resistance of the system are primarily achieved through the yielding of the infill steel plates. However, during an earthquake event, the infill plates at different building stories may not yield simultaneously due to many factors such as overstrength of some infill plates and the actual lateral force distribution which is different from the one assumed in design, possibly resulting in inter-story drift concentrations in the system. This paper investigates the effect of column stiffness on mitigating drift concentration in SPSWs. Based on an example two-story SPSW, mathematical models are derived to characterize the system behavior and quantify the effect of column stiffness on the mitigation of drift concentration. Nonlinear static pushover analyses using finite element models are performed to further validate the developed models. Finally, based on the developed models, parametric analyses are conducted to investigate the effect of column stiffness over a practical range of the considered parameters, followed by a discussion of the minimum SPSW column stiffness specified in North American codes. The results from this investigation show that column stiffness should be a design parameter to ensure a reasonably uniform drift distribution and hence a more uniform infill plate yielding along the height of SPSW buildings.     

抗弯钢框架-密肋网格复合钢板墙抗侧力体系抗震性能理论与试验研究

提出了密肋网格复合钢板剪力墙,并与抗弯钢框架相结合,充分发挥各自的性能。从理论和试验两个方面对其抗震性能进行了研究。其中理论分析主要研究了密肋网格复合钢板剪力墙的受力机制,提出了密肋网格板的构造措施,并通过有限元模型分析了其受力性能;试验研究主要针对一榀双跨两层抗弯钢框架-密肋网格复合钢板剪力墙试件进行拟静力试验,考察其在低周反复荷载作用下的侧向刚度及承载性能、滞回特性、耗能能力及破坏特性等,评价了该体系的抗震性能。研究表明：该体系在弹性阶段主要依靠墙板的剪切机制和钢框架共同承担水平荷载,非弹性阶段区格中钢板的对角斜向拉力带为结构提供侧向承载能力;密肋网格板避免了墙板发生整体剪切屈曲,限制了钢板的面外变形值,提高了其弹性刚度,缓解了墙板拉力带对边框架柱的附加弯矩,保护了主要受力构件,克服了滞回曲线的捏缩现象,显著增强了其耗能能力;钢框架与密肋网格复合钢板剪力墙具有良好的协同工作性能,体系变形能力强,大变形状态下具有稳定的承载性能,安全储备高,是优秀的抗侧力体系;破坏模式为区格中钢板屈曲屈服并撕裂,拉力场效应明显,钢框架梁端及钢框架柱底形成塑性铰。     

柱刚度对钢板剪力墙侧移集中的影响

钢板剪力墙(SPSWs)是一种由边界框架构件包围薄填充钢板组成的抗侧力系统。薄填充钢板屈服引起整体的滞回耗散和抗侧向力。然而,地震时,受很多因素的影响(如填充钢板超强)不同建筑层的薄填充钢板可能不会同时屈服,且实际的侧向力分布与设计时所假定的不同,可能导致建筑整体层间的侧移集中。研究柱刚度对减缓整体侧移集中现象的影响。根据一个两层的钢板剪力墙模型,推导出一个可表示整体性能、量化柱刚度对减缓整体侧移集中现象的影响的数学模型。使用有限元模型来进行非线性静态推覆分析,从而验证改进的模型。最后,根据改进的模型进行参数分析,随后讨论北美标准中规定的钢板剪力墙柱刚度的最小值。研究结果显示,柱刚度应该作为一种设计参数,从而确保一个合理统一的侧移分布,因此,填充钢板会沿钢板剪力墙建筑的高度方向屈服。