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。     

Analysis of reinforced concrete coupled shear wall structures

The ultimate strength analysis of reinforced concrete coupled shear walls with one or two bands of openings requires a two‐stage approach. In the first stage, the analysis of the coupling beams is carried out. This is followed by the analysis of the complete wall in the second stage. A simple approach based on the ‘total moment concept’ for the analysis of coupled shear walls with one or two bands of openings is presented. Experimental results supporting the predictions of the mode of failure and ultimate strength is also presented. This study updates previous research and enhances further understanding of the behaviour of reinforced concrete shear wall structures at ultimate limit states of loading. Copyright © 1999 John Wiley & Sons, Ltd.     

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.     

Analysis of a mono-symmetric core wall structure coupled with connecting beams

An open mono-symmetric core wall coupled with connecting beams is analysed under lateral loading, using Vlasov's thin-walled beam theory. Shearing deformations in the plane of the wall are taken into account, considering geometric compatibility. Coupling beams are treated as a medium with an equivalent stiffness property. Effect of connecting beam stiffness and of shearing deformations on the rotation of the whole system are presented. Inclusion of shearing deformations increases rotation of the structure; this effect being more outstanding in core walls with mono-symmetrical cross-section and those with very stiff connecting beams.     

双肢剪力墙有限元计算模型的研究

在使用有限元分析软件进行分析计算时,连梁有两种建模方式:按框架梁输入和按墙开洞输入。不同的建模方式对应不同的计算模型,不同的计算模型会导致结构性质和构件内力产生较大差异,所以进行双肢剪力墙结构计算时,必须结合实际情况,综合考虑各种因素选择合适的建模方式。本文拟通过SAP2000分析不同跨高比下两种模型的楼层位移、梁端弯矩,进而找出双肢剪力墙如何建立有限元模型的方法。     

大震下RC剪力墙(筒体)结构地震反应分析模型

以足尺框架-剪力墙结构试验为基础,讨论了几种不同的剪力墙宏观模型,通过计算与试验结果的比较发现,纤维墙模型在大震下的计算稳定性较差,单分量模型、多弹簧模型以及所提出的等效纤维柱模型可适用于不同地震水平下剪力墙结构的地震反应分析。探讨了核心筒结构的建模方法以及上述模型在不同地震水平下的适用性。     

考虑地震动摇摆分量作用的输电塔线体系响应

为探究输电塔线体系在地震动水平-摇摆耦合作用下的响应,进行了振动台试验和理论分析。地震动摇摆分量通过小波分析的方法从原始地震记录中取得,此方法以单摆式地震仪在水平和竖向的响应差别为基础,通过摇摆倾斜位移的傅里叶谱和竖向速度相似作验证。采用实际输电塔线体系的简化缩尺模型,进行单塔模型和三塔两线模型在顺线向作用下的振动台试验,考察在地震动水平、摇摆及水平-摇摆耦合作用下的结构响应。推导了地震动水平、摇摆加速度和摇摆位移耦合作用下输电塔线体系的动力方程,在方程的激励项中以等效侧向力的形式考虑摇摆转角位移产生的附加P-Δ效应。研究结果表明：理论分析和试验结果吻合较好,证明了理论分析的正确性;地震动摇摆分量不可忽略,其对输电塔线体系的地震响应影响较大,其中由摇摆转角位移产生的附加P-Δ效应会增大输电塔线体系的动力响应,并造成塔体产生一定程度的非对称位移响应;本次试验中,在多维地震作用下,输电线会减弱输电塔主体结构的水平位移和加速度响应,但相对于水平地震动作用,考虑摇摆分量后,输电线对输电塔主体结构响应的减弱效果将会被削弱。     

轴压比对带PC填充墙的装配式联肢#br# 剪力墙受力性能影响分析

在试验研究的基础上,对带预制混凝土(PC)填充墙的装配式联肢剪力墙进行数值模拟分析,系统研究不同连接方式、轴压比下结构的破坏形态、承载力、刚度、延性等性能。结果表明：PC填充墙的存在可提高结构的承载力、抗侧刚度,刚性连接时结构的周期折减系数建议取0.8～1。随着轴压比的增大,试件的屈服荷载和峰值荷载增大;轴压比小于0.3时,结构的抗侧刚度随轴压比的增大而增大,当轴压比大于0.3时,随轴压比增大,刚性连接下的刚度减小,而柔性连接试件刚度基本不变;结构的延性随轴压比的增大而减小,刚性连接试件的延性系数降低速率高于柔性连接试件,建议刚性连接下,轴压比大于0.3时加强剪力墙边缘构件配筋。     

密肋复合墙体压弯剪复合受力性能非线性数值分析

应用通用有限元程序ANSYS,采用"实体单元-组合式配筋"计算模型,以墙体剪跨比、边框柱截面尺寸及配筋率作为变化参数,对墙体压弯剪复合受力性能进行非线性有限元分析。通过对不同墙体模型的承载力以及墙体截面正应力和应变等计算结果的分析,研究较大剪跨比密肋复合墙体的破坏形态及特征、受剪及受弯承载力的影响因素、压弯极限状态下墙体的应力及应变特征,为复合墙体正截面压弯承载力计算公式及构造措施的建立提供依据。经对比分析表明,有限元计算结果与试验结果吻合较好。因此,采用提出的有限元模型及方法得出的密肋复合墙体压弯剪复合受力性能的非线性有限元分析结果是可靠且可信的。     

Wide-band random excitation of beams and rectangular plates coupled to discrete substructures

Formulation of the title problem using the Green's function of the beam or plate allows solution by the methods of classical modal analysis. These are briefly reviewed in this context and the necessary results are stated for both classically and nonclassically damped systems, the mean square response to stationary excitation being obtained in terms of spectral integrals. Some cases in which these can be evaluated analytically are examined.     

带可更换部件的联肢剪力墙抗震性能研究

钢筋混凝土联肢剪力墙结构在地震作用下,钢筋混凝土连梁和剪力墙的墙脚常遭到严重破坏,修复困难。为此,提出了一种带有可更换连梁和可更换墙脚部件的可恢复功能联肢剪力墙,介绍了带可更换部件的联肢剪力墙的设计方法。为了研究带可更换部件的联肢剪力墙的抗震性能和破坏模式,以一片10层联肢剪力墙为例,对带有可更换部件的联肢剪力墙和传统联肢剪力墙进行了地震反应时程对比分析。计算结果表明,在地震作用下,可更换连梁和可更换墙脚部件先后屈服,破坏集中在可更换部件上,带可更换部件的联肢剪力墙的抗震性能显著提高。     

新型剪力墙体系的设计和试验

主要对新型剪力墙体系进行了设计,研制成功轻骨料混凝土和免拆保温墙模,着重对新型轻骨料混凝土进行了力学性能试验,并且运用有限元软件ANSYS对单片剪力墙进行了受力的数值模拟,通过试验和结构分析,证明该体系可以在工程中应用推广.     

Biaxial and torsional response of inelastic structures under random excitation

Structures under strong motion earthquake excitation often go into the inelastic range, and the restoring force becomes nonlinear and hysteretic. Since only very rarely the excitation direction perfectly aligns with the structural orientation, the response is generally biaxial and torsional motion often becomes important for structures which have geometric of a random vibration method to predict the inelastic response including the biaxial interaction and torsional motion. A previously developed differential equation model for the restoring force and the equivalent linearization solution procedure are generalized for this purpose. The methods are tested using a single-story space-frame and a three-story space-frame with setbacks. Comparisons with Monte Carlo simulations are made and methods for improvement of the accuracy are suggested.     

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。     

联肢剪力墙连梁阻尼器伪静力试验研究

连梁阻尼器属于平面内屈服型软钢阻尼器。通过对11个连梁阻尼器进行伪静力试验研究,结合试验现象及力-位移关系曲线对各型号连梁阻尼器的屈曲和破坏状况观察,判断其工作性态。采用数据拟合法对伪静力试验数据分析得到连梁阻尼器的双线性刚度、极限承载力和等效阻尼比的经验公式,为工程设计提供阻尼器的力学特性和本构关系。文中采用的研究思路为：提取试验结果,有限元模拟、调参,以调参后的有限元模型的解作为精确解,虚拟多种型号阻尼器,计算双线性刚度、极限承载力,回归经验公式,并确定阻尼器耗能能力评价标准。通过伪静力试验得出：双列孔连梁阻尼器的滞回性能良好,呈现整体屈曲;建议采用孔间柱长宽比α>2.5,两列孔的列间距与孔间距之比γ≥1.0,开孔率p∈［5%,20%］的双列孔连梁阻尼器。图19表5参9     

暗支撑“一”字形短肢剪力墙非线性分析

依托ABAQUS有限元分析软件,以一字形短肢剪力墙较薄弱的抗震构件作为研究对象,建立等效模型并模拟分析了该结构在不同轴压比、不同钢筋配筋率情况下的承载、骨架曲线等关键抗震性能指标,并与试验结果进行了对比,得出了轴压比和配筋率对暗支撑一字形短肢剪力墙的抗震性能影响敏度较高的结论。     

剪力墙体系的结构设计体会

从概念设计的角度出发,对剪力墙的受力与计算进行了论述,总结出高层剪力墙的基本设计理念,即在满足建筑平面使用的前提下,合理把握关键部分及次要构件,关键部分加强,耗能部位放松。     

Dynamic response of discretely damped structures under harmonic and random excitation

One way of minimizing the excitation of a structure under dynamic loading is to include viscous dampers, both within the structure and connected to points of support outside the structure. However, the magnitude of the damping required and the position of the damper is not always easily determined. For multi-degree-of-freedom structures, some modes may not be damped while others may be excessively damped. Excessive damping of one mode may also precipitate other modes of vibration. This paper describes an analysis based on the frequency response method for studying the dynamic response of framed structures under both harmonic and random excitation. Studies of a multi-storey frame structure and a cable stayed pedestrian footbridge are described. These studies include investigations of the location and magnitude of the dampers.     

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     

Evaluation of composite shear wall behavior under cyclic loadings

Composite steel shear walls (CSSW) are widely used in civil projects due to its high stiffness and deformability. It can be utilized by either laying a concrete layer connected to the steel plate by shear studs or bonding a Fiber Reinforced Polymer sheet. The present experimental and numerical investigations were focused on the effects of shear studs spacing variation, middle beam rigidity and the method of beam to column connection on the CSSW behavior. Results indicate that increasing the shear studs spacing reduces the slope of load-displacement curve and improves ductility up to a specific studs’ spacing. In addition, the effects of middle beam rigidity and beam to column connections are insignificant on the composite steel shear walls behavior.