Shear strength of the connection between a steel coupling beam and a reinforced concrete shear wall in a hybrid wall system

No specific guidelines are available for computing the shear strength of the connection between a steel coupling beam and a reinforced concrete shear wall in a hybrid wall system. There were carried out analytical and experimental studies on the connection between a steel coupling beam and a concrete shear wall in a hybrid wall system. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the shear strength of the connection between a steel coupling beam and a reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behaviour in the connection between a steel coupling beam and a shear wall, i.e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between a steel coupling beam and a reinforced concrete shear wall. The proposed equations in this study were in good agreement with both our test results and other test data from the literature.     

Panel shear strength of steel coupling beam-wall connections in a hybrid wall system

One of the most common types of hybrid systems is represented by a hybrid coupled shear wall consisting of steel coupling beams and reinforced concrete shear walls, known as a hybrid wall system. This paper addressed the shear strength of connection between structural steel coupling beams and reinforced concrete shear walls. No specific guidelines are available for predicting the panel shear strength of steel coupling beam-wall connections in a hybrid coupled shear wall system. The panel shear strength of steel coupling beam-wall connections in a hybrid coupled shear wall system is examined through results of an experimental research programme where three 2/3-scale specimens were tested under cyclic loading. Panel shear strength reflects enhancement achieved through mobilization of the reinforced concrete panel using face bearing plates and/or horizontal ties in the panel region of steel coupling beam-wall connections. The results and discussion presented in this paper are compared with ASCE design guidelines for RCS composite joints, which form a similar structural system. Finally, this paper provides the background for design guidelines that include a design model to calculate the panel shear strength of steel coupling beam-wall connections.     

双肢剪力墙中连梁延性的研究

对双肢剪力墙的连梁采用数学方法进行了分析,并且考虑在不同情况下连梁所需的延性。     

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.     

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.     

美国组合联肢剪力墙抗震设计方法探讨

基于美国加州建筑规范及其引用的相关设计规程和ASCE组合结构委员会的建议,介绍了由钢筋混凝土剪力墙与钢连梁组合而成的组合联肢剪力墙的抗震设计方法。该方法包括：基于中震的水平地震作用计算、合理耦连比的选择、中震及大震水平作用下钢连梁与剪力墙的抗震性能目标、基于先钢连梁屈服后剪力墙屈服的预定屈服机制的构件设计与验算等。据此,建议我国组合联肢剪力墙的第一阶段抗震设计应基于中震水平而不是小震水平。建议方法可供完善我国组合联肢剪力墙结构抗震设计参考。     

带分段式连梁的钢筋混凝土联肢#br# 剪力墙拟静力试验及数值模拟

文章提出一种由耗能段和承重段组成的分段式钢筋混凝土连梁，通过低周往复加载试验及有限元数值模拟，对带分段式连梁的钢筋混凝土联肢剪力墙试件的抗震性能进行研究。结果表明：连梁耗能段比承重段更早开裂及屈服，且试验结束后裂缝更多更密集，表明耗能段起到主要的耗能作用，而承重段能始终可靠地承受重力荷载；试件的滞回曲线初期较饱满，呈梭形，后期出现明显的捏拢效应，曲线呈倒S形；试件的位移延性达到24左右，极限位移角达到1/40左右，表明其具有良好的变形性能；随着耗能段截面高度的增加，试件耗能能力增强，但承重段损伤加重。     

钢筋混凝土联肢墙小跨高比复合斜筋连梁抗震性能试验研究

钢筋混凝土联肢剪力墙或联肢筒壁中的连梁是抗震关键部件。小跨高比连梁因剪弯比高,不采取特殊措施难以满足高剪力条件下的高延性要求。现行设计规范使用的交叉暗撑连梁虽抗震抗剪能力及延性好,但钢筋绑扎困难;现行规范降低抗剪能力上限、强化配箍要求的普通配箍连梁则抗剪能力过低、延性依然不足。为此,有必要寻求一种不需内力或刚度折减的高抗剪能力、高延性、便于施工的小跨高比连梁设计方案。为适应小跨高比连梁的受力特征,提出一种由交叉斜筋和上、下L形斜筋复合配筋的新设计方案,并完成19个具有不同跨高比、不同剪压比和不同斜筋———L形筋用量比的足尺连梁低周交变加载试验。试验结果表明,采用新方案配筋的连梁具有良好的抗震性能;剪跨比为0.8~2.5的该类连梁在剪压比高达0.3及以上时仍具有不低于4.0~5.0的位移延性,且施工难度明显降低。这种新的连梁配筋方案可推荐用于高抗震等级的建筑结构。     

连梁内设置竖向变形阻尼器的耗能剪力墙体系减震分析与设计

将钢筋混凝土联肢剪力墙在连梁跨中开缝,在缝中设置沿竖向变形的钢阻尼器,从而形成耗能联肢剪力墙体系。在强震作用下,耗能剪力墙中的阻尼器一方面适当削弱联肢剪力墙刚度以降低地震作用,另一方面阻尼器屈服后可耗散部分地震能量,从而减小墙肢及连梁的塑性损伤。将阻尼器与连梁组合为等效连梁,运用等效连续化方法对耗能剪力墙体系的刚度特性与阻尼特性进行了简化分析,对耗能剪力墙体系的减震机理进行了论证,并推导出体系关键参数的计算式。以阻尼器延性系数和联肢墙耦合比为设计控制指标,提出了该耗能剪力墙体系基于性能/需求的设计方法。设计实例表明：所提出设计方法简便可行;在参数设计合理的情况下,建议的耗能剪力墙体系具备良好的减震效果。     

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.     

联肢剪力墙抗震性能研究——试验和理论分析

为考察规范中有关联肢剪力墙设计条款的适用性和验证一种可以考虑墙肢中性轴的移动和连梁中弯曲、剪切和粘结滑移等各类变形的联肢剪力墙模型的可靠性,本文进行了据规范设计的三片联肢剪力墙的低周反复荷载试验,讨论了恢复力模型的形式,并提出一种可以反映墙肢中性轴的移动和连梁的包含弯曲、剪切和滑移各种变形在内的计算模型用于理论分析。试验结果表明,三个试件均不具备其应有的连梁破坏模式和耗能机制。恢复力模型的骨架曲线可采用带有下降段的三线型或四线型,滞回规律至少应由反映刚度退化、滑移和强度退化的三个参数来决定。计算结果与试验结果的相符证明了模型的有效性。     

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.     

组合联肢剪力墙中连梁设计的若干问题

提出了组合联肢剪力墙体系联系度Dc的概念,推导了其计算方法,阐述了联系度在组合联肢剪力墙概念设计中的应用,并讨论了钢连梁或组合连梁的抗震设计、连梁与钢筋混凝土墙肢连接节点的不同构造方式和设计方法.     

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.     

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     

新型组合钢连梁弹塑性状态下的抗震性能研究

通过含有钢筋混凝土连梁、钢连梁与新型组合钢连梁的结构进行试验对比,利用ANSYS软件建立试验模型,进行模拟试验分析,研究新型组合钢连梁在弹塑性状态下的抗震性能.试验结果表明,小跨高比连梁采用新型组合钢连梁,其抗震性能好,适宜剪力墙结构采用.     

剪力墙结构小跨高比连梁研究述评

分类整理了剪力墙结构小跨高比连梁研究的国内外最新文献,从连梁的材料构成、配筋构造形式、试验研究现状、分析计算模型、施工难度及在实际工程中的应用情况等方面进行了比较分析,提出需要进一步研究的问题。     

钢骨混凝土连梁联肢剪力墙抗震性能试验研究及有限元分析

国内已有部分超高层建筑结构采用钢骨混凝土连梁联肢剪力墙,但现行规范尚未对其钢骨含钢率等控制参数给予明确规定。为此,对不同含钢率的钢骨混凝土连梁联肢剪力墙进行了低周反复荷载试验研究、ABAQUS有限元模拟以及变参数分析。分析结果表明：钢骨混凝土连梁联肢剪力墙试件的破坏模式、水平承载力、变形能力和耗能能力明显优于钢筋混凝土连梁联肢剪力墙;由ABAQUS参数分析结果可知,钢骨含钢率应控制在4%~8%之间,且宜增加连梁钢骨腹板的面积。     

Dynamic analysis of non-planar coupled shear walls with stiffening beams using Continuous Connection Method

In this paper, the dynamic analysis of non-planar non-symmetrical coupled shear walls on a rigid foundation has been considered. The analysis deals with coupled shear walls having a finite number of stiffening beams, whose properties vary from region to region along the height. In the analysis, Continuous Connection Method (CCM) and Vlasov׳s theory of thin-walled beams are employed to find the stiffness matrix of the structure. The system mass matrix has been found in the form of lumped masses at the heights where the unit forces have been applied. Following the free vibration analysis, uncoupled stiffness, damping and mass matrices have been found employing the mode superposition method. A time-history analysis has been carried out using Newmark numerical integration method to find the system displacement vector for every time step. Finally, a computer program has been prepared in Fortran language and an asymmetrical example has been solved. The results have been verified via comparisons with those of the SAP2000 structural analysis program using frame method and a perfect match has been observed.