偏心支撑钢框架耗能梁段的设计

偏心支撑钢框架既具有较大的抗侧刚度,同时在大震作用下又具有很好的延性,介绍了偏心支撑钢框架中重要构件耗能梁段的设计方法。     

偏心支撑钢框架设计方法

着重阐述了消能梁段的设计方法 ,其中包括消能梁段的长度确定和截面选择 ,消能梁段的腹板加劲肋、连接和侧向支撑的设计。并对消能梁段以外其它构件的设计方法进行了介绍 ,以增强工程设计人员对该结构体系的了解。     

偏心支撑钢框架能力设计方法研究

结合国内外偏心支撑钢框架结构的最新研究成果以及相关设计规范的规定,对偏心支撑钢框架结构的性能进行分析,介绍偏心支撑钢框架结构的能力设计方法,对我国规范相对落后的部分进行补充,为工程设计提供一些参考。着重阐述耗能梁段,耗能梁段外的梁、支撑、柱和耗能梁-柱节点的设计,同时总结了偏心支撑钢框架结构设计中应注意的问题。     

3种偏心支撑钢框架的塑性设计方法

偏心支撑钢框架是在中心支撑钢框架的基础上发展起来的一种新型结构体系,它能够有效改善钢框架在大震作用下的抗震性能。本文基于已有耗能梁段的塑性设计模型,考虑钢材的应变硬化效应影响,提出了一种改进的偏心支撑耗能梁段塑性模型,并基于此模型对不同形式的偏心支撑钢框架在弯矩、剪力共同作用下的屈服模型进行了研究,推导出其塑性设计公式。     

偏心支撑钢框架结构延性设计探讨

偏心支撑钢框架结构是一种比较理想的抗侧结构体系,尤其适用于高烈度和强震地区,像美国和日本有大量的使用.文章结合耗能梁段的受力特点和破坏情况,为其延性设计提出了一点建议.     

D型偏心支撑钢框架耗能梁段性能研究

通过对具有不同耗能梁段长度的D型偏心支撑钢框架的滞回性能及耗能梁段耗能性能的非线性有限元分析,表明耗能梁段的长度对偏心支撑钢框架的侧向刚度、延性和耗能能力有较大影响。随着耗能梁段长度的增加,D型偏心支撑钢框架的强度、刚度、延性和耗能性能均产生了不同程度的退减现象;耗能梁段越短,其塑性变形越大,进而导致耗能梁段过早塑性破坏的可能性增大。根据有限元模拟结果提出了对耗能梁段长度的设计建议。     

偏心支撑框架的设计方法概述

参考美国抗震规范AISC 341—05和GB 50010—2010建筑抗震设计规范,对偏心支撑框架的设计方法进行探讨,重点介绍了消能梁段、加劲肋的布置、柱、支撑以及消能梁段以外梁段的设计,预期可增强设计人员对该种结构体系设计方法的了解,为同类结构体系的设计提供参考。     

Y型偏心支撑钢框架的受力性能研究

Y型偏心支撑钢框架是最近发展起来的一种新型抗侧力结构体系,具有很好的抗震性能。可以通过改变耗能梁段的截面尺寸和支撑的布置形式来优化结构的抗震性能。本文基于我国现行《抗震规范》建立三个系列的一榀Y型偏心支撑钢框架平面模型,并运用有限元分析软件sap2000对结构进行pushover分析计算,研究了Y型偏心支撑钢框架的耗能梁段长度、腹板高厚比和耗能支撑的布置形式等参数对Y型偏心支撑钢框架结构抗震性能的影响,提出了相应的抗震设计建议。     

耗能梁段长度对K形偏心支撑钢框架抗震性能的影响

分析了K形偏心支撑钢框架中耗能梁段的受力特性,利用非线性有限元程序探讨了耗能梁段长度对K形偏心支撑钢框架刚度、延性及耗能性能的影响,提出了初步设计时耗能梁段长度的取值范围。     

耗能梁段长度对K形偏心支撑钢框架抗震性能的影响

分析了K形偏心支撑钢框架中耗能梁段的受力特性,利用非线性有限元程序探讨了耗能梁段长度对K形偏心支撑钢框架刚度、延性及耗能性能的影响,提出了初步设计时耗能梁段长度的取值范围.     

Y型偏心支撑钢框架受力性能有限元分析

建立了四种Y型偏心支撑钢框架有限元模型,对平面模型框架和三种空间模型框架进行了单向加载和循环加载试验,并对比分析了模型框架的屈服强度、极限承载力、侧向刚度、延性和耗能能力等方面的受力性能差异,得到的结果为工程设计提供了参考。     

Fundamental periods of steel eccentrically braced frames

This paper describes formulation of a hand method that can be used to estimate the computed fundamental periods of vibration of building structures in general and steel eccentrically braced frames (EBFs) in particular. The developed method uses the Rayleigh's method as a basis and utilizes the roof drift ratio (RD_R) under seismic forces as a parameter. To obtain RD_R, more than 4000 EBFs were designed by considering the seismic hazard, number of stories, braced bay width and link length to bay width ratio as prime variables. A model was developed to estimate RD_R, which depends on the rigid plastic deformation mechanism for a typical EBF. The method was verified using design data produced as a part of this work as well as data published in literature. The verifications indicate that the proposed formulation is capable of providing acceptable estimates of the computed period. When compared with existing empirical period–height relationships, the proposed formulation offers closer estimates with reduced scatter. The method was further refined to derive new period–height relationships for two different seismicity regions. The accuracy of the relationship for high seismic regions was verified using measured periods of EBF buildings. Copyright © 2014 John Wiley & Sons, Ltd.     

两种偏心支撑钢框架受力性能对比分析

建立了空间Y型与K型偏心支撑钢框架有限元模型,对两种模型框架进行了单向加载和循环加载试验,对比分析了两种空间偏心支撑框架的屈服强度、极限承载力、侧向刚度、延性和耗能能力等方面受力性能的差异,为工程设计提供参考。     

Recent research on eccentrically braced frames

Recent research developments on eccentrically braced steel frames for seismic design are reviewed. The emphasis is placed on the design of links, which are short sections of beams between columns and braces, and similar elements at eccentric joints. The review includes some highlights of the latest experiments with one-third scale models employing different eccentric bracing schemes, an updated classification of links, and special design requirements for different types of links. Some results are given on recent cyclic tests of full-size links.     

改进加盖板法用于D型偏心支撑结构的抗震性能试验研究

提出一种新型剪切型耗能梁段与柱连接节点——改进加盖板方案,在满足梁端抗弯、抗剪承载力的同时,放松对耗能梁段的约束,使其充分发展剪切塑性变形,耗散更多的地震能量。采用1∶3缩尺模型,将该新型方案用于D型偏心支撑结构中,与传统的D型偏心支撑结构进行了对比试验,结果表明,采用改进加盖板方案的单斜杆偏心支撑结构具有很好的抗侧移刚度和变形能力,并具有足够的抗侧移能力;可以将耗能梁段从柱边移开,从而允许耗能梁段有较大转动,耗散更多的地震能量。同时也给出了改进加盖板方案的设计方法。     

Evaluating response modification factors of concentrically braced steel frames

Response modification factor is one of the seismic design parameters to consider nonlinear performance of building structures during strong earthquake. Relying on this, many seismic design codes led to reduce loads. The present paper tries to evaluate the response modification factors of conventional concentric braced frames (CBFs) as well as buckling restrained braced frames (BRBFs). Since, the response modification factor depends on ductility and overstrength, the static nonlinear analysis has been performed on building models including single and double bracing bays, multi-floors and different brace configurations (chevron V, invert V and X bracing). The CBFs and BRBFs values for factors such as ductility, overstrength, force reduction due to ductility and response modification have been assessed for all the buildings. The results showed that the response modification factors for BRBFs were higher than the CBFs one. It was found that the number of bracing bays and height of buildings have had greater effect on the response modification factors.     

Multi-level enhancement of structural behavior of bracing systems with coupling beams at floor level

Despite good rigidity, braced frames have weak nonlinear behavior and inadequate distribution of ductility in stories, which cause significant structural damage. In this research, a seismic resistant system called coupled concentrically braced frame (CCBF) is developed to enhance the performance of braced frames by coupling them with a beam. In this case, the coupling beams are the primary source for ductility of the system, and after their yielding in more severe earthquakes, the structure continues to benefit from the ductility of the braces as the secondary source; therefore, the system has two-level behavior caused by different probable seismic excitations. In this case, in addition to maintaining the stiffness of the two concentrically braced frames, the coupling beams resist against the movement of the braced frames, and as a result, the stiffness of the system is increased. Therefore, lighter elements can be used to resist lateral loads. Linear and nonlinear analyses of CCBF, and its comparison with other braced frames, indicate that participation of the coupling beams provides an adequate stiffness and ductility. These frames have more stable nonlinear behavior than conventional ones and continue their nonlinear behavior even after fracture of coupling beams in severe earthquakes.     

偏心支撑框架设计新进展

介绍了美国新标准对偏心支撑框架设计的修订,并对我国抗震规范和有关规程对偏心支撑框架的修订作了说明。与过去的规定相比,新规定对构件的内力增大系数有明显降低。说明了降低的原因,并介绍了偏心支撑框架构件和连接设计的有关要求和应考虑的问题,可供设计人员参考。     

V型偏心支撑钢框架抗震性能非线性时程分析

针对V型偏心支撑钢框架的不同耗能梁段长度,运用有限元分析软件SAP2000对相应的算例进行非线性时程分析。通过对构件内力、节点位移等计算结果的分析,并与D型和K型偏心支撑钢框架非线性时程分析的结果进行比较,得到了一些结论,以供工程设计人员参考。