Elasto-plastic analysis of coupled shear walls

The problem of yielding in the components of coupled shear walls under strong earthquake excitation reduces, for purposes of design, to estimation of ductility requirements. To provide a basic treatment of this problem, a simplified elasto-plastic analysis of coupled shear walls subjected to lateral loading is suggested. It is based on an approximate distribution of the coupling shear for post-elastic behaviour. A continuous lamina replaces the coupling beams, and hinges are permitted in the walls as well as in the beams. Four examples are included to demonstrate the application of the proposed analysis and to assess the validity of the approximations involved. Results confirm the proposed analysis to within good accuracy.     

带竖缝钢筋混凝土剪力墙板的简化静力分析模型

带竖缝钢筋混凝土剪力墙板在弹性状态下有较大刚度,而在弹塑性状态下又有较好的延性,是一种抗震性能较好的结构单元。但由于缺少有效的分析模型,带竖缝钢筋混凝土剪力墙板在国内的工程应用很少。根据带竖缝钢筋混凝土剪力墙板的V-u曲线,按照侧向刚度相同的原则将之等效为偏心交叉支撑简化模型,并给出了简化模型的截面特性和材料本构关系曲线。通过算例统计分析给出了偏心距的取值范围及简化分析模型的适用范围。与更接近于实际墙板特性的等效带竖缝板模型的算例对比分析表明,在框架结构静力分析中采用简化模型模拟带竖缝钢筋混凝土剪力墙板是可行的。     

Static analysis of laterally arbitrarily loaded non-planar non-symmetrical coupled shear walls

This paper describes the static analysis of non-planar non-symmetrical coupled shear walls, employing the continuous connection method in conjunction with Vlasov's theory of thin-walled beams. All previous authors concerning themselves with symmetrical systems, the present authors give particular attention to non-symmetrical systems in both the formulation and the numerical applications. The method of analysis presented was compared with SAP2000 structural analysis program (frame method). The results obtained showed good agreement, verifying the accuracy of the proposed method, which can efficiently be used in the predesign computations of tall buildings.     

Free vibrations of stiffened coupled shear walls

This paper presents the free vibration analysis of stiffened coupled shear walls based on a discrete–continuous approach. The stiffened system is reinforced by an additional stiffening beam at some level of the structure. This induces additional axial forces, and thus reduces the bending moments in the walls, as well as helping to reduce the lateral deflection. The effect of the stiffening beam on the free vibration characteristics of coupled shear walls is studied, and numerical investigations show that the natural frequencies of vibration can be significantly increased. The optimal position for the stiffening beam to increase as far as possible the first natural frequency of vibration is also presented. © 1998 John Wiley & Sons, Ltd.     

带暗支撑剪力墙损伤累积静力弹塑性分析

在多垂直杆剪力墙单元模型的基础上进行改进,把多垂直杆的轴向刚度和剪切刚度相结合,即每根垂直杆传递轴力的同时还传递剪力,考虑钢材和混凝土损伤累积效应对剪力墙的影响,在上述基础上提出考虑材料损伤累积效应的带暗支撑剪力墙模型,模型更接近带暗支撑剪力墙的受力性能。利用该模型编制的相应程序,对两片分别带有型钢暗支撑和钢筋暗支撑的剪力墙模型进行弹塑性静力加载数值模拟分析,计算结果和试验结果吻合较好,说明方法应用可行。     

Interaction based analysis of continuous transfer girder system supporting in-plane loaded coupled shear walls

This paper presents a method of analysis for a structural system of coupled shear walls supported on continuous transfer girder framing into columns. It is proposed that the analysis of the system be discretized into two parts. The coupled shear wall is analysed first based on the continuum technique assuming an ideal fixed support. Charts are presented to modify the continuum forces for the interactive effect of the non-rigid support. The internal forces of the walls at the level of the transfer girder are defined as the interface forces of the girder and the coupled shear walls. These forces are then used in the analysis procedure for the supporting structure. Finite element simulation is used to capture and interpret the interaction mechanism of the system. Effects of different wall and support system characteristics on the structural behaviour of the system are also discussed. Copyright © 1998 John Wiley & Sons, Ltd.     

Stiffening of laterally loaded coupled shear walls on elastic foundations

An investigation is made of the relative effectiveness of using either a top or bottom connecting beam to stiffen a pair of laterally loaded coupled shear walls supported on independent elastic foundations. By basing the analysis on the continuous medium approach, a closed solution to the problem is achieved. A numerical example for a typical structure illustrates the influence of the stiffening beams on the forces and deformations in the structure for two different soil conditions.     

On the accuracy of the continuum method for analysis of coupled shear walls of unequal width

The continuous medium technique has been widely used in the preliminary analysis and design of coupled shear walls in tall buildings by practising engineers for many years. One of the basic assumptions made when using this approximate method is that the coupling beams deform with points of contraflexure at mid-span. However, when there is a non-negligible difference between the stiffness's of the structural walls connected by the coupling beams, the points of contraflexure of the beams can move off-centre, and hence noticeable error in the analysis may occur. This paper presents a study on the accuracy of the continuous medium technique for the preliminary analysis of concrete coupled structural walls with unequal width. Comparison of the analytical results between the method and the wide-column analogy has been made. Recommendations for using the continuum method to analyse coupled shear walls are presented.     

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.     

双肢型钢混凝土短肢剪力墙抗震性能试验及数值模拟

通过一榀双肢实腹式型钢混凝土短肢剪力墙模型试件的低周反复荷载试验,揭示该类双肢墙的破坏机制及抗震性能.试验结果表明:试件从型钢混凝土连梁屈服形成塑性铰,再到墙肢屈服发生破坏;试件延性系数、等效黏滞阻尼系数分别为3.58和0.191,表明该类双肢墙结构的破坏表现为强墙肢弱连梁型,具有较好的抗震性能.考虑到连梁破坏时只有少...     

Hysteretic analysis of thin steel plate shear walls

Thin steel plate shear walls (TSPSWs) are especially concerned due to the economic factor and excellent energy dissipation capacity. TSPSWs commonly define as steel plate with height-to-thickness ratio over 300. The post-buckling capacity, deformability and energy dissipation capacity of TSPSWs are now accepted by structural engineers. This brings about evident economic benefit. This paper presents a finite element analysis of TSPSWs under cyclic loading. The calculated results are compared with experimental results to validate its accuracy. Then based on the finite element model, the influence of height-to-thickness ratio and span-to-height ratio on the hysteretic behavior of TSPSWs is analyzed. Also, the influence of column moment rigidity on the development of tension field is studied. At last, a new simplified Combined Strip Model is introduced which is suitable for the hysteretic analysis of TSPSWs. Based on the Combined Strip Model, a formula for calculating shear strength is proposed, which considers the compression effects of TSPSWs.     

Thin steel plate shear walls behavior and analysis

Steel plate shear walls have been used in buildings in North America and Japan. Until recently, the design practice has been to limit the strength of the wall to the buckling strength of the plate. The post-buckling strength of thin plates subjected to shear has been recognized for more than 60 years, since it was outlined by Wagner in the early 1930s. Tests of a quarter and one third scale specimens of thin steel plate shear walls under cyclic loading were performed; the tests are described and the results are summarized. An analytical model to determine the behavior of thin steel plate shear walls was developed and is given. The model is capable of depicting the behavior of walls with plates welded or bolted to the surrounding beams and columns of the building frame. Comparisons between the analytical and experimental results are made.     

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 behavior of RC coupled shear walls repaired with CFRP laminates having variable fibers spacing

The paper considers the seismic analysis of reinforced concrete (RC) coupled shear walls structures strengthened by bonded composite plates having variable fibers spacing. An efficient analysis method that can be used regardless of the sizes and location of the bonded plates is proposed in this study. In the numerical formulation, the adherents and the adhesives layers are all modeled as shear walls elements, using the mixed finite element method. Dynamic analysis was performed to investigates the influence of the fibers redistribution of the bonded plates on the lateral deflections of RC coupled shear walls. This conceptual study has demonstrated the feasibility of mitigating the seismic response of RC coupled shear walls building structures by using composites plates having variable fibers spacing.     

Optimized use of the outrigger system to stiffen the coupled shear walls in tall buildings

Based on the conventional yet accurate continuum approach, a general analysis is presented for a pair of coupled shear walls, stiffened by an outrigger and a heavy beam in an arbitrary position on the height. Subsequently, a parametric study is presented to investigate the behavior of the structure. The optimum location of the outrigger and the parameters affecting its position were also investigated. The results showed that the behavior of the structure can be significantly influenced by the location of the outrigger. It was also indicated that in most ordinary cases the best location of the structure to minimize top drift is somewhere between 0·4 to 0·6 of the height of the structure. Though this method is not a substitute for the finite element method, it gives an initial simple solution to determine the size and position of outrigger, stiffening beam and coupled shear walls in the preliminary design stages. Copyright © 2004 John Wiley & Sons, Ltd.     

配筋砌块剪力墙有限元分析与试验比较

在具体试验设计配筋砌块砌体剪力墙的基础上,使用ABAQUS软件对其进行数值模拟,对配筋砌体砌块剪力墙的滞回曲线、骨架曲线和延性进行分析研究,包括模型的选取与建立,有限单元的选取等,比较计算结果与试验结果,证明有限元分析模型可靠有效.     

预制圆孔板剪力墙非线性有限元分析

采用ANSYS有限元软件,对一个设置现浇边缘构件的单片预制圆孔板剪力墙试件进行了在定轴压力和单调递增水平力作用下的非线性分析,与拟静力试验结果进行了比较,两者符合较好,验证了计算模型和参数取值的合理性。在此基础上,对四个设置现浇边缘构件的单片及双片预制圆孔板剪力墙试件进行了非线性有限元分析。结果表明,无论是按弯曲破坏还是按剪切破坏设计的试件,都是墙底截面开裂,边缘构件沿高度出现水平裂缝,圆孔板剪力墙以斜裂缝为主,斜裂缝数量多,布满整个墙面,没有出现集中的塑性铰,有利于抗震耗能;双片墙试件的开裂荷载和最大荷载显著高于单片墙试件的。结论可为预制圆孔板剪力墙这种新型装配整体式住宅建筑体系的推广应用提供理论依据。     

Experimental investigation of composite shear walls under shear loadings

One of the efficient methods for improving the seismic behaviour of high-rise buildings is using Composite Steel Plate Shear Wall (CSPSW). In this paper, extensive experimental studies of one and three-story CSPSWs with the scale of 1:3 and 1:4, together with stress equations of each element are reported. The experimental results indicate that this system has reliable behaviour if the columns have high bending stiffness. Also bolts spacing to plate thickness ratio has direct relationship with system ductility. However, plate yield load has an inverse relationship with this ratio. In this system, plate stiffening requirement is obtained with minimum reinforcement for reinforced concrete, though for damage prevention high strength concrete is preferred. Also, the results show a good agreement for the recommended values of (b/t) by an AISC code for preventing plate buckling.     

钢筋混凝土剪力墙火灾后抗剪承载力研究

考虑了高温后混凝土和钢筋的力学特性,给出了火灾后钢筋混凝土剪力墙抗剪承载力的计算公式.公式中,高温后剪力墙截面混凝土抗拉强度的平均降低系数采用分层法计算得到,并以表格的形式给出了不同迎火面温度、受火时间及剪力墙厚度的降低系数值以方便实际工程使用.利用该公式计算得到了火灾后钢筋混凝土剪力墙抗剪承载力,与试验结果比较发现,...