短肢剪力墙抗震试验研究

通过两个短肢剪力墙试件的低周反复试验,研究了短肢剪力墙的破坏模式、抗震性能及计算方法,并用ANSYS程序进行了非线性有限元分析。     

钢桁架连梁-联肢剪力墙耗能机理及抗震性能试验研究

对设置全钢桁架连梁和设置钢筋混凝土、钢桁架混合连梁的双层联肢剪力墙平面结构进行了拟动力试验和低周反复荷载试验,研究了不同工况地震波作用下剪力墙的时程响应,以及其破坏机理、承载力、滞回延性性能、耗能机理、刚度及强度退化机理。试验结果表明:全部设置钢桁架连梁的剪力墙的刚度分布合理,耗能机理及刚度强度退化机理符合联肢剪力墙抗震设计的要求。大震时,在保证较高耗能能力的同时能够维持较高的承载力和刚度,持续约束墙肢,抗震性能优于混凝土连梁联肢剪力墙体系,是一种较理想的连梁设置方案。     

短肢剪力墙抗震性能研究综述

阐述了国内外研究者对短肢剪力墙抗震性能的研究现状,并分析了研究中存在的不足,探讨了短肢剪力墙抗震性能研究中的若干关键问题,展望了短肢剪力墙结构抗震性能研究的发展前景。     

对称双肢短肢剪力墙的低周反复荷载试验研究

介绍了两榀对称双肢短肢剪力墙的拟静力试验,研究了短肢剪力墙的破坏形态、滞回特性和整体性系数对其弹塑性性能的影响。试验结果表明,短肢剪力墙是一种强肢弱梁型的联肢墙,连梁的屈服先于墙肢的屈服,且连梁屈服后,由于内力重分布的作用,使材料的性能得到充分的发挥。短肢剪力墙结构具有较好的延性和耗能能力。对于层数、层高、墙肢尺寸、材料及配筋都相同的短肢剪力墙,其承载能力随整体性系数的增加而增加,而延性却随之减小。     

低周反复荷载下短肢剪力墙抗震性能研究

研究了钢筋混凝土短肢剪力墙(RC-SLW)在低周反复荷载下的整体工作性能、破坏形态和滞回特性。结果表明:短肢剪力墙是一种强肢弱梁型的联肢墙,连梁的屈服先于墙肢的屈服,该结构具有较好的耗能能力和延性,为其推广使用提供了依据。     

联肢弯剪型钢板剪力墙抗震性能试验研究

联肢钢板剪力墙结构是将2片钢板剪力墙通过钢连梁连接形成的抗侧力结构。通过对1榀1/3缩尺的4层联肢弯剪型钢板剪力墙试件进行低周往复加载试验,从滞回曲线、骨架曲线、延性、承载力及刚度退化、耗能能力等方面研究了该结构体系的抗震性能,并且对试件的屈服顺序和变形模式进行了分析。结果表明：联肢钢板剪力墙试件的延性系数达到5.03,承载力退化系数均大于0.96,承载力和刚度退化稳定,等效黏滞阻尼系数达到0.25以上,表明联肢弯剪型钢板剪力墙具有优越的抗震性能。加载过程中,连梁先于墙板发生屈服,墙板先屈曲后屈服,此后柱脚和横梁相继屈服。连梁的引入改变了结构的屈服机制,提高了整体的延性和耗能能力,能够组成多道抗震防线,且试件整体最终也体现出合理的破坏机制。整体侧移曲线呈弯剪变形模式。该试验研究更加贴合实际工程中联肢钢板剪力墙结构的应用情况,为联肢钢板剪力墙结构的进一步研究和应用提供了试验基础。     

劲性钢筋混凝土低剪力墙抗震性能试验研究

为了改善钢筋混凝土低剪力墙的抗震性能，可在钢筋混凝土低剪力墙内设置型钢骨架，成为劲性钢筋混凝土低剪力墙。试验结果表明，劲性钢筋混凝土低剪力墙的抗震性能明显优于钢筋混凝土低剪力墙。同时，在分析试验结果的基础上，建议了劲性钢筋混凝土低剪力墙的抗剪承载力计算公式和用于动力分析的恢复力模型     

新型钢筋混凝土叠合剪力墙抗震性能试验研究

进行了2榀新型叠合剪力墙的低周反复试验,研究了叠合剪力墙的破坏形态、滞回特性、变形能力、刚度退化、耗能能力.试验结果表明,剪式支架能够较好的连接两侧预制板,并使其与现浇层协同工作,保证叠合剪力墙的整体工作性能.     

内置钢板钢筋混凝土剪力墙抗震性能研究

设计16个内置钢板钢筋混凝土剪力墙(简称SPRCW)试件,进行低周反复加载试验研究。根据试验现象与试验数据得到的滞回曲线、骨架曲线、延性系数、等效粘滞阻尼系数等参数,从强度、变形和能量等三个方面判别和评定试件的抗震性能;比较不同参数如高宽比、墙体厚度、钢板厚度等条件下试件的工作性能;研究细部构造措施如拉结筋和钢板上焊接栓钉等对于剪力墙受力破坏特征以及抗震性能方面的影响;对比SPRCW与普通钢筋混凝土剪力墙发现,钢板对于提高构件的抗震性能效果十分明显。通过对试验数据的拟合,研究了构件在地震作用下的恢复力特性,确定结构构件恢复力的计算模型,为结构非线性时程分析提供理论依据;利用试验数据拟合了内置钢板钢筋混凝土剪力墙的受剪承载力公式,可为制定该类型构件的相关规范提供参考。     

地震力作用角度对短肢剪力墙抗震性能的影响

通过低周反复试验研究了加载角度对"一"字形截面钢筋混凝土短肢剪力墙抗震性能的影响,加载角度为0°,25°,45°。记录了试件由开裂、屈服到破坏的整个过程,观察到不同角度加载造成的剪力墙不同的破坏模式,可以发现,短肢墙的破坏形式由弯剪破坏到弯曲破坏变化。定量分析试件的恢复力曲线(即滞回曲线和骨架曲线)、延性、耗能能力等指标发现,随着加载角度的增大,构件的极限承载力变小,极限位移、延性、耗能能力增大。     

国外木框架剪力墙理论分析模型综述

在学习国外有关木框架剪力墙理论分析模型文献资料的基础上,总结了国外近三十年来在木框架剪力墙理论分析模型方面的研究成果,这些研究成果可为我国木结构的理论研究提供借鉴。     

Seismic behaviour of coupling beams in a hybrid coupled shear walls

Steel coupling beams in a hybrid coupled shear wall provide a viable alternative for concrete coupling beams coupling individual reinforced concrete wall piers. Due to the lack of information, current design methods for calculating embedment lengths are silent about cases in which hybrid coupled walls have connection details of stud bolts and horizontal ties. In this work, an analytical study was carried out to develop a model for calculating the embedment lengths of embedded steel sections. Five models for calculating embedment lengths in a hybrid coupled wall are developed as variations of the Prestressed Concrete Institute guidelines for steel brackets attached to reinforced concrete columns. In addition, experimental studies on the hybrid coupled shear wall were carried out. The main test variables were the ratios of the coupling beam strength to the connection strength. The test results indicate that it is more advantageous to design the coupling beams as shear yielding members since the shear-critical coupling beam exhibits a more desirable mode of energy dissipation than the flexure-critical coupling beam.     

Novel continuum models for coupled shear wall analysis

Replacement beam formulations represent a family of 1D continuum models suitable for approximate analyses of the structural arrangements of buildings. In this paper, an energy equivalence approach is applied to coupled shear walls to develop suitable replacement beam models. Assuming properly compatible coupling fields between walls, a novel three‐field coupled two‐beam approach, therein providing shear and axial deformations, is proposed. The corresponding mathematical formulation provides closed‐form solutions for simple loading cases with homogenous properties. Considering slender coupled shear walls, as typically found in tall buildings, the coupled two beams can be reduced to a two‐field formulation, i.e., a parallel assembly of an extensible Euler–Bernoulli beam and a rotation‐constraining beam. The latter model is solved analytically, and expressions for the tip displacement and base bending moment are presented. A finite element model is then presented and demonstrated to be an efficient tool for static and dynamic analyses. The effects of the axial deformation and degree of coupling on slender coupled shear wall responses are described as being dependent upon two suitable parameters. Various approximate relations are also proposed for design purposes. Finally, the validity of both analytical solutions and the finite element model is confirmed via numerical examples. Copyright © 2015 John Wiley & Sons, Ltd.     

A transfer matrix approach to free vibrations of coupled shear walls

A conceptually simple and computationally efficient numerical model, based on the transfer matrix technique, is proposed for the prediction of the elastic behaviour of coupled shear walls. The model developed allows for: variation of geometric and material properties with the height; shear as well as axial deformation of both walls and beams; a certain degree of rigidity at their joints; and subsidence as well as elastic movement of the foundations. The method is numerically implemented and applied to the evaluation of natural frequencies and modes of free vibrations of the structure. Good agreement of its predictions with experimental results confirms its accuracy and efficiency. Further comparisons with previously obtained numerical results lead to an assessment of the effect of shear deformation of the walls on the higher frequencies and demonstrate the capacity of the method to yield all types of vibrational modes within a predefined frequency range. The paper also assesses the effect of elastic foundation properties on the lower natural frequencies.     

Seismic behavior of code designed steel plate shear walls

The AISC Seismic Design Provisions now include capacity design requirements for steel plate shear walls, which consist of thin web plates that infill frames of steel beams, denoted horizontal boundary elements (HBEs), and columns, denoted vertical boundary elements (VBEs). The thin unstiffened web plates are expected to buckle in shear at low load levels and develop tension field action, providing ductility and energy dissipation through tension yielding of the web plate. HBEs are designed for stiffness and strength requirements and are expected to anchor the tension field formation in the web plates. VBEs are designed for yielding of web plates and plastic hinge formation at the ends of the HBEs.This paper assesses the behavior of code designed SPSWs. A series of walls are designed and their behavior is evaluated using nonlinear response history analysis for ground motions representing different hazard levels. It is found that designs meeting current code requirements satisfy maximum interstory drift requirements considering design level earthquakes and have maximum interstory drifts of less than 5% for maximum considered earthquakes. Web plate ductility demands are found to be significantly larger for low rise walls than for high rise walls where higher modes of vibrations impact the response. The percentage of story shear resisted by the web plate relative to the boundary frame is found to be between 60% and 80% and is relatively independent of panel aspect ratio, wall height, or hazard level, but is affected by transitions in plate thickness. Maximum demands in VBEs in design level shaking are found to be considerably less than those found from capacity design for SPSWs with 9 or more stories.     

联肢剪力墙连梁阻尼器地震模拟试验研究

采用拟动力试验方法,对连梁阻尼器进行地震模拟试验研究,模拟结构的真实地震响应。首先,选取简单的单片双肢剪力墙结构模型,每层附加一个连梁阻尼器,选取El Centro和Taft两条地震波,分别进行35gal、140gal、220gal和620gal拟动力试验,构成8种试验工况;随后将其等效成单质点附加阻尼器体系,单质点系作为数值子结构,附加的阻尼器作为试验子结构,进行拟动力子结构试验,同时进行数值仿真验证。对比数值模拟与试验结果得出：拟动力子结构试验可以真实模拟结构地震响应;地震波输入过程中,连梁阻尼器性能稳定,无局部屈曲,对结构的减震效果良好,地震动能量输入越大,阻尼器发挥的作用越大。图10表4参7     

An investigation on the behavior of stiffened coupled shear walls considering axial force effect

In most of tall buildings, the main contribution of lateral loads is carried by coupled shear walls. In some cases, the necessary stiffness to withstand the lateral load may not be afforded due to low depth of connecting beams. In order to increase the capacity of the coupled shear walls, beams with high stiffness are added to the system at particular levels. Hence, stiffened coupled shear walls (SCSW) will be produced. Such walls are under axial load resulting from their weight, and this axial load affects the behavior of walls because of their excessive height. In this paper, a new method considering the effect of axial force for geometrically nonlinear analysis of the SCSW has been presented. A computer program has been developed in matlab , and numerical examples have been solved to demonstrate the reliability of this method. The results of the examples show the agreement between the present method and the other methods given in the literature. The effects of the various positions and rigidities of the stiffening beam on the internal forces and the lateral deflection of the structure considering axial force effect have also been investigated. Copyright © 2012 John Wiley & Sons, Ltd.     

Seismic behavior of coupled shear wall structures with various concrete and steel coupling beams

A novel 2‐level yielding steel coupling beam (TYSCB) has been developed to enhance the seismic performance of coupled shear wall systems. The TYSCB consists of a shear‐yielding beam designed to yield first under minor earthquakes and a bend‐yielding beam designed to yield under severe earthquakes. A comparison of seismic behavior of 4 20‐storey coupled shear wall structures with reinforced concrete coupling beams, complete steel coupling beams, fuse steel coupling beams, and TYSCB is presented. The dimensions and force‐displacement curves of these coupling beams are first designed. Nonlinear dynamic analyses on these structures are carried out under minor and severe earthquakes. The seismic behavior of these models is studied by comparing their storey shear forces, storey drift ratios and ductility demands. The results show that the base shear and storey drift of the structure with TYSCB under both minor and severe earthquakes are less than those of structures with concrete coupling beams and complete steel coupling beams. Furthermore, the ductility demand of coupled shear walls with TYSCB subjected to severe earthquakes can be greatly released compared with those using fuse steel coupling beams. This indicates that the proposed TYSCB has a better balance between ductility demand and energy dissipation, compared to traditional steel coupling beams.     

Seismic design method and experimental study of composite steel plate-concrete coupled shear wall systems

钢板混凝土联肢组合剪力墙是一种具有“双重防线机制”的优良抗震结构体系,其理论研究已经滞后于工程实践的发展,传统的基于强度的抗震设计方法难以从抗震耦合机制层面解决连梁和组合墙肢的匹配问题。为此提出以耦连比为基本设计参数,以连梁-墙肢“双重防线机制”为性能目标的钢板混凝土联肢组合剪力墙抗震设计方法。基于此方法,设计原型结构,并按原型结构底部五层的联肢墙设计制作1∶4缩尺试件,对试件施加往复荷载,考察试件的整体屈服机制。试验结果表明,结构体系通过钢连梁的剪切变形和墙肢底部的塑性铰变形来耗散能量,实现了连梁-墙肢“双重防线机制”,验证了该设计方法的合理性。     

地震作用下钢筋混凝土联肢剪力墙的应力分析

应用有限元分析软件ANSYS,分析了某钢筋混凝土联肢剪力墙在水平地震作用下的应力分布情况,研究得出:位于整片墙体底部及中部的洞口边角处表现出了明显的应力集中,控制连梁的跨高比,不仅可以避免连梁本身发生剪切破坏,而且可使其两侧墙肢仍具有较强的抗震能力。