土木毕业设计外文翻译-钢板剪力墙中间水平边界单元的容量设计

钢板剪力墙中间水平边界单元的容量设计摘要容量设计原则要求韧性形变, 2005 AISC 和 2001 CSA抗震设计规范要求：除了在填充板完全产生地震载荷作用下的情况下产生塑性铰，中间水平边界元素钢板剪力墙设计基本上应保持弹性。然而,在对全面的两层 SPSW测试期间出现的意想不到的失败观察指出当前设计方法并不一定达到中间 HBE预期的性能。本文分析模型估算 HBEs可靠地达到设计能力。这些模型可以与中间 HBE线性梁模型塑性机制假定相结合,并能够防止出现塑料铰。使用该模型预测设计应力可与非线性有限元分析的结果相比较。可以观测出良好的结果。最后,该模型也被用来解释观察到的中间 HBE过早失效。CE数据库主题标题：剪力墙;钢板;地震工程;抗震设计。关键词：剪力墙;钢板; 容量; 设计;地震工程;抗震设计。介 绍钢板剪力墙（SPSW）包含了非加强的加密钢面板，它由被称为垂直边界元素的柱子和被称为水平边界元素（HBE）的梁所包围。这些面板可以扣在剪切和随后形成对角张力领域抵抗侧向力。过去在美国,加拿大,日本,台湾,和其他国家的实验研究表明,SPSW 可以表现出较高的初始刚度并以延性的方式表现,并且使大量的滞回能量消散。对于新建筑的设计以及对现有建筑的改造而言它成为一个可行的选择。分析研究 SPSWs也验证了有用的模型设计和分析。最近有关SPSWs的设计规范由加拿大标准协会提供钢结构极限状态设计，同时由美国钢结构协会提供钢结构建筑抗震规定。创新的 SPSW设计也被提出并由实验验证从而扩大 SPSWs的适用性。然而可能限制这种结构体系被广泛接受的一些障碍仍然存在。特别是,仍有不确定性的抗震性能中间水平边界元素，尤其对于那些具有较少梁的连接形式。例如,意想不到的破坏发生在 SPSW全部两层的中间水平边界元素。这表明当前设计方法可能会导致中间水平边界元素无法满足延性需求。值得注意的是,中间水平边界元素加密板上方和下方的相反方向的锚固面板只有一侧。简单模型使用线元素边界框架不能产生令人满意的 HBE设计结果。由于内在的塑料铰链 HBE建模的复杂性，因此无法解释上述观察到中级 SPSW的 HBE的过早失效。非线性有限元有限元分析使用三维壳元素可用于提供更准确的估计设计结构 HBEs，但是过于繁琐和广泛的使用这个简单的设计方法了。因此,有必要开发一个更合理准确和更有效的方法来为 HBEs设计荷载。以上方法是文中所提到的。应注意,由于空间的限制,一般情况下 RBS与HBEs相连接。但等效程序 HBEs没有与 RBS联系。在这里,基于预期的塑形机理和叠加原理,对于中间的轴向和剪切力 HBE应该使用力图分析。塑性铰在 HBE中应该避免。简单的力图提出了确定在时刻 VBE的图像。最后验证上述分析模型使用非线性有限元分析,在容量设计过程应考虑塑形铰链的强度受双轴和剪切应力条件的影响。最后,测试 SPSW的水平边界单元应使用该模型用来检查，从而解释观察到的无法预期的失败。预期机制与填充板屈服力对多层 SPSWs的理想塑性结构施加横向荷载，使每一层的均匀填充板屈服。它为滞后能量在整个建筑高度的分布提供了可能。 （与软弱层的塑性机制不同，在 VBEs中塑性铰出现在一个单独的层）为了多层 SPSW出现令人满意的预期机制，对于沿着 VBEs和 HBEs的填充板所施加的荷载产生的屈服力，在第 i层为：这些都是通过分解填充板屈服应力得到的，出现在从垂直到水平的一个角度，垂直分量沿 VBEs和 HBE作用。每单位长度屈服力的这些组分包括填充板厚度的函数，填充板的屈服强度，以及填充板的设计屈服应力与名义屈服应力的比值。HBE的轴向力用于估计中间 HBE的轴向力的分析模型已经开发了如图 2所示的子系统。将公式 5、11、12 相结合，使用-和+分别表示压缩和拉伸，3 通过轴向作用预测所得到的下列方程，是中间 HBE在任意位置的轴向力方程。容量设计方法基于本文制定的分析模式，承载力计算的程序在 SPSWs中对于中间 HBEs用 RBS进行连接。它不同于目前的设计，首先它考虑减少 HBE的塑性力矩强度，考虑 HBE的轴向载荷、剪切力的存在，与垂直应力;其次能够捕获的事实，即垂直拉力场的所得到的分量不等于通过 HBE的每一端的反力; 最后它发现了 HBE中塑性铰位置的变化。具有 RBS连接的中间 HBE容量设计的过程显示于图 17，本过程的设计的步骤概述如下。步骤 1：通过公式 14计算填充板的屈服力。步骤 2； 假设一个中间 HBE横截面。步骤 3：通过公式 13确定 HBE的轴向力。步骤 4:使用 Qu 和 Bruneau 2008 年提出的程序确定网络垂直应力。步骤 5：选择符合规范标准的几何形状，这一形状应减少突出。例如使用FEMA 350规范。步骤 6：根据图 16，通过公式 35和公式 36确定塑性铰的塑性截面模量和位置。步骤 7：假设设计过程的初始迭代使塑性铰的塑性力矩减少。步骤 8：通过公式 18确定塑性铰的剪切力。步骤 9: 基于 Qu 和 Bruneau 2008 年提出的方法计算在塑性铰塑性降低时的力矩。如果所计算出的因素足够接近步骤 7中的假定，则继续进行设计。否则，返回步骤 7修改假定的塑性减少时的力矩。步骤 10：通过公式 20计算 HBE中最大力矩的位置。如果得到的结果是否定的，这意味着最大弯矩超出量程，则转到步骤 11。否则，计算在最大弯矩位置处塑性减少的因素，并检查公式 26。如果满足公式 26，则继续设计。否则，返回到第 2步并修改假定的 HBE横截面。步骤 11：通过公式 18计算表面剪力。步骤 12：确定 HBE表面塑性力矩减少的因素。步骤 13：通过公式 33和公式 34计算 HBE表面的抗弯强度。步骤 14：通过公式 31和公式 32计算 HBE表面的弯矩设计值。步骤 15：比较从步骤 13和 14所得出的实际强度和设计值。如果实际强度比设计值大，完成设计。否则，返回到第 2步并修改假设 HBE横截面。应当注意的是，力图中没有考虑重力载荷，因为在 SPSWs中它们通常是相对较小的。然而，如果需要的话，可以通过考虑将使填充板屈服的垂直力分量施加到中间 HBE上。此外，在本文中在推导中忽略了应变强化，例如在验证 FE时的钢被假定具有的优越弹塑性本构关系。但是，为了实现容量设计，当通过FEM350的规定考虑应变强化时，应该纳入对于 RBS塑性铰的强度判定。本文尚未包括在内的另一个考虑是沿 HBE的鱼型板的影响，其用于连接填充板。然而这种影响是可以忽略不计的（Qu and Bruneau 2008） 。此外锚固的 HBEs，作为中间 HBEs的一种特殊情况，也可以通过所提出的程序分析，并将其视为作用在拉力场的一面。对本测试中的中间 HBE 进行裂缝检查在二层 SPSW的测试过程中，使用 RBS连接的中间的 HBE，在其底部凸缘两端出现完整的断裂，但没有在梁翼缘地区出现断裂。尽管许多因素可能导致中间 HBE的意外的损坏，对于 VBE表面的抗弯强度不足是一个值得研究的因素。初步评估可以通过将设计时的要求与 VBE表面的可用抗弯强度比较得出。基于在图 17中所示的中间的 HBE设计过程，得到和表 4所示的弯曲的要求和原始的 HBE的强度。在这里为简单起见，材料应变硬化，复合板，与配套板桁架的影响被忽略了。请注意，这些效应导致在 VBE表面出现更高的塑性铰，并且需要的设计要求。出于比较的目的，该设计与重新设计的中间的 HBE的强度也在表 4中提供。，如前面所述，重新设计的 HBE是 W24*76构件。如表 4所示在合适 VBE面上，原始的 HBE的抗弯强度比需求要小。这可以解释在测试过程中观察到的意外故障。相比较而言，虽然存在更高的要求，重新设计的 HBE的优势是比要求的强度更高，这意味着不可能观察到过早的失效。结果本文所提出的分析模型来估计具有 RBS连接的 HBE的设计应力，这一模型基于所述塑性机制和简单力图。这一设计方法可以实现容量设计。此过程可以防止在跨 HBE的部分出现塑性铰，同时确保每一时刻都有足够 VBE。有限元分析被用来验证所提出的方法。使用本文所提出的知识和方法，对在测试 SPSW的中间 HBE的行为进行了检查，并对观察到的屈服模式和过早断裂进行了解释。Capacity Design of Intermediate Horizontal Boundary Elements of Steel Plate Shear WallsBing Qu, M.ASCE1; and Michel Bruneau, M.ASCE2Abstract: Consistent with capacity design principles and requirements of ductile behavior, the 2005 AISC and 2001 CSA seismic design codes require that the intermediate horizontal boundary elements HBEs of steel plate shear walls SPSWs be designed to remain essentially elastic with the exception of plastic hinges at their ends when the infill plates fully yield under seismic loading. However, the unexpected failure observed during the tests on a full-scale two-story SPSW suggested that the current design approach does not necessarily lead to an intermediate HBE with the expected performance. This paper presents analytical models for estimating the design forces for intermediate HBEs to reliably achieve capacity design. Those models combine the assumed plastic mechanism with a linear beam model of intermediate HBE considering fully yielded infill panels and are able to prevent in-span plastic hinges. Design forces predicted using the proposed models are compared with those from nonlinear finite element analysis. Good agreement is observed. Finally, the proposed models are also used to explain the observed premature failure of intermediate HBE.DOI: 10.1061/ASCEST.1943-541X.0000167CE Database subject headings: Shear walls; Steel plates; Earthquake engineering; Seismic design.Author keywords: Shear walls; Steel plates; Capacity; Design; Earthquake engineering; Seismic design.Introduction A steel plate shear wall SPSW consists of unstiffened infill steel panels surrounded by columns, called vertical boundary elements VBEs, and beams, called horizontal boundary elements HBEs. These panels are allowed to buckle in shear and subsequently form diagonal tension fields to resist lateral forces. Past experimental studies in the United States, Canada, Japan, Taiwan, and other countries have shown that SPSW can exhibit high initial stiffness, behave in a ductile manner, and dissipate significant amounts of hysteretic energy, which make it a viable option for the design of new buildings as well as for the retrofit of existing constructions a list of past implementations and literature reviews is available in Sabelli and Bruneau 2007. Analytical research on SPSWs has also validated useful models for the design and analysis of this system Thorburn et al. 1983; Elgaaly et al. 1993; Driver et al. 1997; Berman and Bruneau 2003b. Recent design procedures for SPSWs are provided by the CSA Limit States Design of Steel Structures Canadian Standards Association CSA 2001 and the AISC Seismic Provisions for Structural Steel Buildings American Institute of Steel Construction AISC 2005. Innovative SPSW designs have also been proposed and experimentally validated to expand the range of applicability of SPSWs Berman and Bruneau 2003a,b, 2008; Vian and Bruneau 2005.However, some impediments still exist that may limit the widespread acceptance of this structural system. In particular, there remain uncertainties regarding the seismic behavior of intermediate HBE particularly for those having reduced beam section RBS connections. For example, unexpected failures have occurred in the intermediate HBE of a full-scale two-story SPSW experimentally investigated by Qu et al. 2008, which indicates that current design approaches do not necessarily lead to HBEs that meet the requirements of ductile behavior. Note that intermediate HBEs are those having infill panels above and below by opposition to anchor HBEs that have panels only on one side.Simple models using line elements for boundary frame members e.g., models conventionally used in SAP2000 are not capable of producing satisfactory results of HBE design forces due to the intrinsic complexity in modeling the strength of plastic hinges in HBE and consequently fail to explain the aforementioned observed premature failure in intermediate HBE of the SPSW. Nonlinear finite element FE analysis using three-dimensional shell elements can be used to provide more accurate estimates of design forces for HBEs but is too tedious for broad use for this simple design purpose. Therefore, there is a need to develop a reasonably accurate and more efficient method to estimate the design loads for HBEs.Such an approach is developed and proposed in this paper. Note that due to space constraints here, this paper focuses on the general case of HBEs with RBS connections. Equivalent procedures for HBEs without RBS connections i.e., a special case of the general formulation presented here are presented by Qu and Bruneau 2008. Here, based on the expected plastic mechanism and the principle of superposition, the axial and shear forces in intermediate HBE are determined using free-body diagrams. Ways to avoid in-span plastic hinge in HBE are addressed. Simple free-body diagrams are proposed to determine the moment demands at VBE faces. Following verifications of the above analytical models using nonlinear FE analysis, capacity design procedures taking into consideration the strength of plastic hinges subjected to biaxial and shear stress conditions are proposed. Finally, the intermediate HBE of the tested SPSW is examined using the proposed models to explain the unexpected failure observed.Expected Mechanism and Infill Panel Yield ForcesThe desirable plastic mechanism of multistory SPSWs subjected to lateral loads Berman and Bruneau 2003b involves uniform yielding of the infill panels over every story Fig. 1. It provides for possible distributed hysteretic energy over the entire building height as opposed to a soft-story plastic mechanism in which plastic hinges form in VBEs at a single story. For a multistory SPSW that satisfactorily develops the expected mechanism, the distributed loads applied along the VBEs xci and yci and HBEs xbi and ybi from infill panel yielding at the ith story areThese are obtained by resolving the infill panel yield forces, occurring at an angle from the vertical into horizontal and vertical components acting along the VBEs and HBEs. Such components of yield forces per unit lengths are a function of infill panel thickness, twi, yield strength of infill panels, f yp, and the ratio of expected to nominal yield stress of infill panels,（Ryp Berman and Bruneau 2008）.Resulting Axial Force in HBE The analytical models to estimate axial forces in intermediate HBE have been developed for each subsystem shown in Fig. 2. These axial effects predicted using Eqs. 5, 11, and 12 are then combined, considering an arbitrary sign convention i.e., “” and “+” for compression and tension, respectively, resulting in the following equation for the axial force at any location of intermediate HBE:Capacity Design Procedures :Based on the analytical modes developed in this paper, capacity design procedures are proposed for intermediate HBEs having RBS connections in SPSWs. It differs from the current design approach in that it i considers reduced plastic moment strength of HBE to account for the presence of axial load, shear force, and vertical stresses in HBE; ii is able to capture the fact that resultant action of the vertical tension field components is not equally resisted by each end of HBE; and iii accounts for the variation of plastic hinge location in HBE. The procedure for capacity design of an intermediate HBE having RBS connections is illustrated in Fig. 17. Design steps of this procedure are outlined belowStep 1: Calculate the infill panel yield forces per Eqs. 14.Step 2: Assume an intermediate HBE cross section.Step 3: Determine the axial force in HBE per Eq. 13.Step 4: Determine the vertical stresses in HBE web using the procedure proposed by Qu and Bruneau 2008.Step 5: Select the flange reduction geometries in compliance with the design specifications and guidelines such as FEMA 350 Federal Emergency Management Agency FEMA 2000.Step 6: In accordance with Fig. 16, determine the plastic section modulus and location of plastic hinge per Eqs. 35 and 36.Step 7: Assume plastic moment reduction factors of the plastic hinges RBSR and RBSL for the initial iteration of the design process.Step 8: Determine the shear forces at plastic hinges perEq. 18.Step 9: Based on the approaches proposed by Qu and Bruneau 2008, calculate the plastic moment reduction factors at plastic hinges. If the calculated factors are close enough to those assumed in Step 7, continue the design. Otherwise, return to Step 7 and modify the assumed plastic moment reduction factors.Step 10: Calculate the maximum moment location in HBE per Eq. 20. If the obtained result is negative, which means the maximum moment develops out of span, go to Step 11. Otherwise, calculate the plastic moment reduction factor at the maximum moment location and check Eq. 26. If Eq. 26 is satisfied, continue the design. Otherwise, return to Step 2 and modify the assumed HBE cross section.Step 11: Calculate the shear forces at VBE faces per Eq. 18.Step 12: Determine the plastic moment reduction factors at VBE faces i.e., R and L.Step 13: Calculate the flexural strengths at VBE faces per Eqs. 33 and 34.Step 14: Calculate the moment demands at VBE faces per Eqs. 31 and 32.Step 15: Compare the strengths and demands obtained from Steps 13 and 14, respectively. If the strengths are greater than the demands, complete the design. Otherwise, return to Step 2 and modify the assumed HBE cross section. It should be noted that gravity loads have not been considered in the free-body diagrams, as they will usually be relatively small in SPSWs. However if so desired, they can be considered by adding them to the vertical components of the infill panel yield forces that are applied to the intermediate HBE. Additionally, derivations in this paper neglect strain hardening since steel in the verification FE example was assumed to have an elastoperfectly plastic constitutive behavior. However, to achieve capacity design, the factor, Cpr, to account for strain hardening as per FEMA 350 FEMA 2000 should be incorporated into determination of the plastic hinge strength in RBS. Another consideration that has not been included is the effect of fish plate along HBE that is used to connect the infill panels; however, that effect was shown to be negligible Qu and Bruneau 2008. Furthermore, anchor HBEs, as a special case of intermediate HBEs, may be also considered by the proposed procedure with a tension field acting on only one side.Examination of Intermediate HBE Fractures in TestsAs described in Qu et al. 2008, during testing of a two-story SPSW, the intermediate HBE, which used RBS connections, developed complete fractures at the ends of its bottom flange, but no fractures developed in the reduced beam flange regions. Although many effects may have contributed to this unexpected failure of intermediate HBE, flexural strength deficiency at VBE face is a factor worthy of investigation.A preliminary assessment can be made by comparing the design moment demands and available flexural strengths at the VBE faces. Based on the intermediate HBE design procedure illustrated in Fig. 17, t