外挂再生混凝土墙板钢框架结构抗震性能有限元分析

在外挂再生混凝土墙板钢框架结构拟静力试验研究的基础上,采用有限元程序对试验试件进行了非线性分析,重点研究结构的滞回性能、钢框架的应力分布、外挂墙板及柱脚的变形形态等,继而对改进设计试件和外挂墙板挂点位置、再生混凝土强度、外挂墙板厚度和高跨比等参数试件进行了拓展分析。结果表明:有限元分析能较好地模拟结构的滞回性能,承载力与试验结果差值在3%以内,试件变形与试验现象吻合较好;沿外挂墙板对角线预埋X形钢板,及在下部外挂节点柱翼缘焊接加劲肋等改进设计,可以明显降低外挂墙板混凝土的开裂、减小柱翼缘的局部弯曲变形等;外挂墙板挂点位置、再生混凝土强度及外挂墙板厚度等设计参数对结构滞回性能的影响较小,而高跨比对结构滞回性能的影响较大。     

钢板剪力墙结构半刚性框架与内嵌墙板间的相互作用性能研究

为研究半刚性框架与钢板剪力墙结构内嵌墙板间的相互作用性能,完成了一榀1∶3比例单跨3层半刚性框架钢板剪力墙结构低周反复荷载试验研究。获得了结构的抗震性能和破坏模式,探究了框架梁、柱、墙板及梁柱节点的局部力学性能,分析了结构的破坏顺序和构件间的传力机理。研究结果表明:该结构具有良好的塑性变形能力和抗震性能,半刚性框架和墙板协同工作良好,结构安全储备较高。内嵌墙板的设置缓解了节点区自身的延性要求,框架承担95%以上的倾覆弯矩,水平荷载由双重抗侧力体系承担,内嵌墙板作为主要抗侧力构件承担约75%剪力。试件整体面内呈弯曲破坏,但是后期钢框架柱面外弯扭较大。通过有限元分析,研究了柱柔度系数、钢板高厚比和梁柱连接特性对钢板剪力墙结构性能的影响。框架梁柱连接刚度对结构体系承载能力的影响与柱的刚度和内嵌墙板的厚度有关。这种影响随着柱刚度增加和内嵌墙板厚度减小而增大。柱的柔度系数为2.5时,柱整体无明显的内凹变形,此时梁柱节点铰接连接更改为刚性连接时,试件承载能力增加小于10%。     

预制装配式剪力墙结构墙板节点抗震性能研究

为掌握预制装配式剪力墙结构墙板节点的抗震性能,对2个现浇试件和2个预制装配式试件进行了拟静力试验.结合非线性分析手段,从承载能力、变形能力、受力机理以及破坏模式等方面综合分析了其抗震性能,并初步探讨了墙板连接钢筋的合理直径.分析结果表明:与现浇试件相比,预制装配式试件承载能力较高,位移延性系数相同,滞同环均较饱满,具有...     

带有新型SIP墙板的框架结构抗震性能研究

介绍了带有新型SIP墙板的钢筋混凝土框架结构的低周反复荷载试验,4个试件分别为一榀空框架试件、一榀未开洞的新型SIP墙板框架试件和两榀在不同位置开洞的新型SIP墙板框架试件,且4个试件的钢筋混凝土框架设计均相同,对比4个框架试件的抗震性能,得到了新型SIP墙板对框架结构抗震性能的影响。观察试验现象及分析试验结果表明,新型SIP墙板作为填充墙板对框架结构的延性、强度、耗能等抗震性能是有利的,同时新型墙板与框架结构之间的连接方式是可靠的。     

复合墙板计算模型与试点工程动力特性分析

本文将均质化理论引入混凝土灌芯纤维增强石膏板(简称复合墙板)的计算。建立了复合墙板的代表性体积单元(RVE)模型,应用有限元分析程序ANSYS对此RVE模型进行模拟,获得其等效弹性常数,为结构的有限元计算提供了有效途径。对一复合墙板结构试点工程进行动力特性测试,测试结果与均质化的计算结果比较吻合,表明这种模型用于计算复合墙板结构的可行性。最后将复合墙板结构与钢筋混凝土剪力墙结构的动力反应特性进行了比较,结果表明复合墙板结构具有优于钢筋混凝土剪力墙结构的抗震性能。     

密肋复合墙板耗能性能及地震损伤分析

根据15榀1/2比例密肋复合墙板在单调及低周反复荷载作用下的试验结果,对这种新型复合墙板的破坏形态、滞回性能、耗能能力和累积损伤模型等进行了分析,探讨了墙板累积损伤的发展过程和发育规律,提出了阶段损伤指数的概念,并通过损伤模型计算的破损结果与试件实际破坏特征对比,确定了墙板的阶段损伤界限值,可供工程实际抗震设计和评估参考。     

节能墙板对RC框架抗震性能影响的试验研究

介绍了一榀RC框架和三榀带康尼节能墙板RC框架的低周往复加载试验,研究了康尼节能墙板对RC框架结构承载力、刚度和抗震性能的影响,得到了RC框架和带节能墙板RC框架的滞回性能。其中,三榀带节能墙板的RC框架分别以不同连接方式制成。试验发现,3种强弱不同连接方式的节能墙板对RC框架的各阶段共同工作都起了一定作用,墙板都没有发生破裂,试件破坏机理相同。在试验研究的基础上,给出了带这种节能墙板RC框架的设计建议。     

钢结构建筑轻质砂加气混凝土墙体的抗震性能试验研究

本文介绍了一钢结构建筑轻质砂加气混凝土外墙板和砌块填充墙的足尺模型振动台试验，并通过试验结果分析，重点研究砌块填充墙的抗震性能、砌块墙体与墙板墙体抗震性能的对比以及两者对钢结构动力特性的影响对比。文中得出了与带墙体钢结构抗震设计有关的结论。     

外包钢框架的预制EPS混凝土墙板抗震性能试验研究

由于预制EPS混凝土墙板内部不锈钢龙骨只承受平面外风荷载作用,墙板内部EPS混凝土墙块的侧向变形能力决定了此种墙板在地震作用下的工作性能。因此,本文进行了4片外包钢框架素EPS混凝土墙块的试件的拟静力试验,研究了其在低周反复荷载作用下的破坏机理、变形能力、延性、滞回特性以及能量耗散系数等。试验结果表明:预制EPS混凝土墙板侧向变形满足规范的要求,纤维板与EPS混凝土墙块连接性能良好,而且纤维板的蒙皮效应对墙体抗震性能贡献明显,适当增大高宽比对于提高EPS混凝土墙块的整体抗震能力作用显著。     

空腔结构复合填充墙-钢框架抗侧力性能试验研究

通过空腔结构复合填充墙-钢框架和同尺寸纯钢框架的对比试验，分析了空腔结构复合填充墙-钢框架的抗侧力性能和滞回性能。研究结果证明空腔结构复合填充墙是一种理想的抗侧力体系，可用于多层或小高层钢结构住宅，作为结构的抗侧力构件。     

Interaction between cladding and structural frame observed in a full‐scale steel building test

Interaction between the external wall cladding and the seismic load resisting frame was examined in a full‐scale cyclic loading test of a three‐storey steel building structure. The building specimen had Autoclaved Lightweight Concrete (ALC, also designated as Autoclaved Aerated Concrete) panels installed and anchored to the structural frame as external wall cladding, using a standard Japanese method developed following the 1995 Kobe earthquake. ALC panelling is among the most widely used material for claddings in Japan. In the test, the ALC panel cladding contributed little to the stiffness and strength of the overall structure, even under a very large storey drift of 0.04 rad. No visible damage was noted in the ALC panels other than minor cracks and spalling of the bottom of the panels in the first storey. Consequently, in a Japanese steel building with properly installed ALC panel cladding, the structural frame is likely to be little affected by its cladding, and the ALC panels are capable of accommodating the maximum storey drift generally considered in structural design without sustaining discernible damage. Copyright © 2006 John Wiley & Sons, Ltd.     

Cladding influence on dynamics response of tall buildings

Precast concrete panels form attractive facades for steel frame buildings and are generally regarded as non-structural by structural engineers. However, panels have been found to add lateral stiffness until their capacity or that of their connections is exceeded. Consequently, the computed dynamic response based on a model of the structural framing alone may be quite different from that experienced by the actual structure. As a case study, the influence of precast concrete panels on lateral and torsional stiffness of a 25-storey building was investigated. The effect of cladding on dynamic properties and linear seismic response was explored by varying panel stiffness. Cladding stiffness was added to the bare frame model until analytical frequency values matched vibration test results. Then, using the cladding stiffness values obtained, an accidental eccentricity between centres of mass and rigidity at each floor level was imposed and linear seismic response computed. Torsional response effects were increased substantially. Finally, a modified cladding panel connection was developed based on previously-reported studies for panelized construction. The influence of the proposed connection on overall structural response was determined for different ground motion inputs.     

Role of wall panel connections on the seismic performance of precast structures

Past seismic events, including the 2009 L’Aquila earthquake and the 2012 Emilia earthquake, clearly demonstrated the inadequacy of the current design approach for the connection system of the cladding wall panels of precast buildings. To clarify this problem the present paper investigates the seismic behaviour of a traditional precast structural frame for industrial buildings with a new type of connection system of cladding panels. This system consists of a statically determined pendulum arrangement of panels, each supported with two hinges to the structure, one at the top and one at the bottom, so to have under seismic action a pure frame behaviour where the wall panels are masses without stiffness. Adding mutual connections between the panels, the wall cladding panels become part of the resisting structure, leading to a dual frame/wall system or to a wall system depending on the stiffness of the connections. The seismic behaviour of this structural assembly is investigated for different degrees of interaction between frame and panels, as well as for an enhanced solution with dissipative connections. The results of nonlinear static (pushover) analyses and nonlinear dynamic analyses under recorded and artificial earthquakes highlight the role of the wall panel connections on the seismic behaviour of the structural assembly and show the effectiveness of the dual frame/wall system with dissipative connections between panels.     

Cyclic tests on a hybrid coupled wall utilizing a rocking mechanism

A new type of hybrid coupled wall system, consisting of rolled steel coupling beams, reinforced concrete (RC) wall piers, and concrete‐filled tube (CFT) short columns, is introduced. In this new system, the bases of the wall piers are connected to the base beams only through CFT short columns, unlike conventional coupled walls. Yield occurs in the coupling beams and the short columns; hence, in the RC wall piers, only minimum cracking appears. A total of four subassembly specimens, designed to fail in various collapse mechanisms, were cyclically loaded under constant axial force. A benchmark specimen showed ductile behavior with large energy dissipation until fracture occurred in the coupling beam. In the specimen designed to fail in shear in its CFT, substantial axial shortening was observed, but the overall behavior was ductile. Behavior of specimens with small amounts of section steel in the wall panel fringe, or with thin wall panels, also showed ductile behavior, but the strength and energy dissipation were significantly smaller than other two specimens. An analytical model was proposed for a frame analysis program using fiber elements to simulate elastic–plastic behavior of the system. Design methods to prevent shear failure of CFT and RC panels are suggested using the analytical and test results. Copyright © 2008 John Wiley & Sons, Ltd.     

Experimental and analytical investigation of seismic stability of masonry walls at Beauharnois powerhouse

The seismic stability of the facade brick-masonry walls of the machinery building of the Beauharnois powerhouse near Montreal, Quebec, Canada were investigated numerically by use of non-linear models and applying experimental methods on site and on the IZIIS’ seismic shake-table. The dynamic properties of the machinery building were obtained by ambient vibration measurements. Based on these results, a model of a representative part of the building, consisting of steel frames and brick masonry wall, was designed and constructed to the reduced scale at the IZIIS’ Dynamic Testing Laboratory and then tested on the two-component shake-table. The geometry of the original structure was completely scaled to 1/3, consisting of many realistically simulated details such us: brick layers, steel columns, openings, window frames, steel connectors between brick layers, number of layers, brick dimensions, etc. The material used for the model was: original steel for the frame structure and bricks of reduced mechanical properties for the masonry wall, close to the similitude requirements according to the Backingham’s theorem, valuable for adequate artificial—mass simulation model as well as true replica simulation model. More than 50 seismic tests were performed considering the design earthquake Nahanni NWT, H1, with a time scaling factor of 3^1/2, and acceleration scaling factor 1, according to the model design rules. The intensity of the applied input earthquake excitation was from 0.05 to 1.2 g. The design peak acceleration of Nahanni earthquake was 0.2 g. The cracks development was stated at 0.7 g input acceleration. These were concentrated around the openings. No collapse happened even under the strongest earthquake input. The numerical part of this paper deals with formulation/application of the critical plane approach to seismic analysis of masonry structures. Starting with the constituents, i.e. mortar and bricks, the macroscopic strength properties of masonry were established based on numerical homogenization. Generally, based on all the performed experimental tests, considering some simplifications and assumptions in the constructing details, as well as in the design of the model, the global conclusion is that the existing wall is very well incorporated in the steel structure of the powerhouse. The complementary stiffness of the steel frame and the brick masonry wall produces interactive deformation of the system. Only local cracking and relative displacement between the wall and the steel frames could be expected in the case of a strong earthquake.     

Experimental research on the seismic behavior of CSPSWs connected to frame beams

The seismic performance of composite steel plate shear walls (CSPSWs) that consist of a steel plate shear wall (SPSW) with reinforced concrete (RC) panels attached to one or both sides by means of bolts or connectors is experimentally studied. The shear wall is connected to the frame beams but not to the columns. This arrangement restrains the possible out-of-plane buckling of the thin-walled steel plate, thus significantly increasing the bearing capacity and ductility of the overall wall, and prevents the premature overall or local buckling failure of the frame columns. From a practical viewpoint, these solutions can provide open space in a floor as this type of composite shear walls with a relatively small aspect ratio can be placed parallel along a bay. In this study, four CSPSWs and one SPSW were tested and the results showed that both CSPSWs and SPSW possessed good ductility. For SPSW alone, the buckling appeared and resulted in a decrease of bearing capacity and energy dissipation capacity. In addition, welding stiffeners at corners were shown to be an effective way to increase the energy dissipation capacity of CSPSWs.     

Experimental simulation of base‐isolated buildings pounding against moat wall and effects on superstructure response

Base‐isolated buildings are typically important facilities expected to remain functional after a major earthquake. However, their behavior under extreme ground shaking is not well understood. A series of earthquake simulator experiments were performed to assess performance limit states of seismically isolated buildings under strong ground motions, including pounding against a moat wall. The test setup consists of a quarter scale three‐story frame isolated at the base with friction pendulum bearings and a moat wall model. An effort was made to properly scale the strength and the stiffness of the frame relative to the bearings properties from a professionally designed isolated three‐story steel intermediate moment‐resisting frame so that realistic yielding mechanisms can be observed. The moat wall was modeled as either a rigid triangle steel stopper or a concrete wall of various thicknesses with soil backfill. The moat wall gap was set to various displacement increments to examine the sensitivity of this parameter and also to assess the effects of impact on the superstructure at different velocities. The test results indicate that the contact forces are largely dependent on the gap distance, impact velocity and wall flexibility and, in extreme cases, pounding can induce yielding in the superstructure. Copyright © 2012 John Wiley & Sons, Ltd.     

SRC框支剪力墙结构地震反应简化分析模型研究

针对钢筋混凝土高层框支剪力墙结构抗震性能差的缺点,提出采用型钢混凝土（SRC）梁柱框支剪力墙,试验结果表明了其良好的抗震性能。提出了框支剪力墙结构地震反应简化分析模型,将结构简化为由墙单元和框支单元组成的弹簧体系,墙单元采用二元件模型。推导了框支单元刚度矩阵,基于理论公式和试验结果给出了框支单元恢复力模型。根据提出的简化模型,编制了结构地震反应时程分析程序。程序计算结果与ETABS分析结果及振动台试验结果吻合较好,为进一步对SRC框支剪力墙结构进行地震反应分析提供了理论基础。