巨型框架-支撑结构的非线性地震反应分析

巨型框架-支撑结构体系是一种新型的巨型结构体系,是在吸取巨型框架结构体系和巨型桁架结构体系优点的基础上被提出的。对巨型框架-支撑结构进行了罕遇地震下的弹塑性时程分析。结果表明,巨型框架-支撑结构的动力性能优越,是一种高效的巨型结构体系。     

SMA复合支座-巨型框架结构体系减震效果分析

在研究形状记忆合金（SMA）绞线-叠层橡胶复合支座基础上,本文提出了SMA复合支座-巨型框架减震结构体系,建立了SMA复合支座-巨型框架减震结构体系的计算模型和运动方程,研究了该结构的动力反应特性,并将其与普通巨型框架结构、应用普通橡胶支座巨型框架结构进行了非线性时程对比分析。结果表明,SMA复合支座-巨型框架减震结构体系能有效地减小结构的地震响应,同时避免了地震时主次结构之间产生碰撞破坏。     

巨型框架-次框桁架结构抗震性能分析

提出了巨型框架—次框桁架结构体系。采用ANSYS有限元程序对巨型框架—次框桁架结构体系进行了抗震动力时程分析,讨论了该结构体系在多条地震波作用下的动力位移及内力等地震响应。计算结果表明,巨型框架—次框桁架结构体系具有良好的抗震性能,能够提高巨型框架结构的抗震性能,不但可以有效地降低结构构件的地震内力,同时也不会给主框架结构体系的布置带来较大的影响,巨型框架—次框桁架结构是一种抗震性能良好的结构体系。计算结果对巨型结构的抗震设计有较大的参考价值。     

巨型框筒部分悬挂结构控制体系地震反应特性及阻尼控制研究

本文提出巨型框筒部分悬挂结构新体系，研究这种结构体系对地震反应特性，提出用阻尼器进行巨型框筒部分悬挂体系地震反应的控制方法，采用结构动力学有限元方法，建立空间分析模型，对结构体系进行地震随机振动分析、时程分析和地震反应谱分析。分析结果表明，这种结构体系能有效地减小结构的地震响应，最后研究了影响控制效果的主要因素及控制器参数的影响规律。     

强震作用下超高层建筑结构MSCSS的响应特性研究

笔者根据超高层巨型建筑结构体系的构造特点,论述了将结构振动控制原理融入巨型结构本身构造之中的构造新结构体系的方法,并采用这一方法提出了巨子型有控结构体系MSCSS(Mega-sub controlled structural system),分析了MSCSS的构造原则及控制理论背景,研究了MSCSS在罕遇地震及超罕遇地震(加速度峰值达到1000g)时的结构响应控制特性、塑性铰发生规律及结构灾变情况。通过与巨型框架结构的灾变情况相比,表明了MSCSS抵御地震作用的高可靠性及良好的经济性,也表明了将结构振动控制原理融入结构自身的构造之中、通过结构自身的功能单元实现结构响应控制的方法是合适的,是研究超高层建筑结构新体系的有效途径之一。     

悬挂阻尼控制结构体系巨型框架地震响应分析

提出一种巨型悬挂阻尼控制结构体系，采用结构动力学有限元方法对结构体系进行了地震随机振动分析、时程分析和地震反应谱分析，分析结果表明，这种结构体系能有效地减小结构的地震响应。最后讨论了影响控制效果的参数。     

巨型框架-耗能支撑结构的减震性能分析

对巨型框架-耗能支撑结构新体系进行了罕遇地震作用下的弹塑性时程分析,研究该体系的减震性能和耗能支撑的不同布置方式对结构的减震效果。结果表明:如果耗能支撑布置位置得当,可以用较少的耗能支撑个数达到较好的减震效果;巨型框架-耗能支撑结构不但可以减少原巨型框架-支撑结构的层间侧移,还可以减少其底部剪力和顶层加速度反应的峰值。     

基于复频响应传递函数的巨型框架隔震悬挂结构参数分析

本文针对巨型框架单段隔震悬挂结构采用静力凝聚方法建立了两质点简化计算模型,基于所建立的参数化特征值方程分析了悬挂子结构与主结构间的质量比和频率比对结构体系自振频率的影响。通过相对坐标系下运动方程的拉普拉斯变换建立了结构体系相对位移复频响应传递函数,采用数值计算方法分析了悬挂子结构与主结构间质量比、频率比和悬挂子结构阻尼比对相对位移反应的影响。分析结果表明:频率比较小时,结构体系的一阶频率与悬挂子结构自振频率相当;具有较大质量比或频率比的巨型框架隔震悬挂结构可简化为单质点计算模型;高频区域的减震效果相比低频区域的更加突出;以巨型框架较小相对位移反应为控制目标时,质量比与频率比存在最佳取值范围;增加悬挂子结构阻尼比有利于提高结构体系的减震效果。     

剪力墙结构、框架填充墙结构模型模拟地震试验研究

对三种结构体系的模型，即钢筋混凝土剪力培结构、钢筋混凝土框架砖填充壤结构和钢框架混凝土填充墙结构模型，进行了地震模拟振动台试验研究．三种结构的模型均为４层，１／３几何比例，整体尺寸相同，按静力等强度原则进行设计。利用５ｍ×５ｍ液压振动台逐渐增大输入地震的峰值加速度直至模型破坏，在试验过程中测量并比较三种模型在弹性和开裂等状态时加速度、位移、应变的反应情况，并用微幅激振测定模型在相应状态下动力特性的变化，从而综合比较和研究它们的地震反应、破坏机理和抗震能力。     

中间柱型黏滞阻尼器装配式钢框架减震性能研究

为研究黏滞阻尼器与装配式钢框架中间柱式连接的整体抗震性能,且跨内不同位置的减震效率,设计出3个足尺的三层装配式钢框架结构:无控结构、柱靠边布置结构和柱居中布置结构,利用振动试验台对其进行测试,对比研究模型结构的地震反应,并采用有限元软件SAP2000进行模拟验证。试验和数值模拟结果均表明:无控结构在地震输入下地震反应较大,对其附设黏滞阻尼器后,地震响应得到有效控制,且柱居中布置结构的附加阻尼比高于柱靠边布置结构,其减震效果更优。     

Seismic response of steel frame structures with hybrid passive control systems

The concept of the hybrid passive control system is studied analytically by investigating the seismic response of steel frame structures. Hybrid control systems consist of two different passive elements combined into a single device or system. The hybrid systems investigated in this research consist of a rate‐dependent damping device paired with a rate‐independent energy dissipation element. The innovative configurations exploit individual element strengths and offset their weaknesses through multiphased behavior. A nine‐story, five‐bay steel moment‐frame was used for the analysis. Six different seismic resisting systems were analyzed and compared. The conventional systems included a special moment‐resisting frame (SMRF) and a dual SMRF–buckling‐restrained brace (BRB) system. The final four configurations are hybrid passive systems. The different hybrid configurations utilize a BRB and either a high‐damping rubber damper or viscous fluid damper. The analyses were run in the form of an incremental dynamic analysis. Several damage measures were calculated, including maximum roof drift, base shear, and total roof acceleration. The results demonstrate the capability of hybrid passive control systems to improve structural response compared with conventional lateral systems and to be effective for performance‐based seismic design. Each hybrid configuration improved some aspect of structural response with some providing benefits for multiple damage measures. The multiphased nature provides improved response for frequent and severe seismic events. Copyright © 2011 John Wiley & Sons, Ltd.     

Seismic response of steel structures with seesaw systems using viscoelastic dampers

Vibration control systems are being used increasingly worldwide to provide enhanced seismic protection for new and retrofitted buildings. This paper presents a new vibration control system on the basis of a seesaw mechanism with viscoelastic dampers. The proposed vibration control system comprises three parts: brace, seesaw member, and viscoelastic dampers. In this system, only tensile force appears in bracing members. Consequently, the brace buckling problem is negligible, which enables the use of steel rods for bracing members. By introducing pre‐tension in rods, long steel rods are applicable as bracing between the seesaw members and the moment frame connections over some stories. Seesaw mechanisms can magnify the damper deformation according to the damper system configuration. In this paper, first, the magnification factor, that is, the ratio of the damper deformation to the story drift, is delivered, which includes the rod deformation. Results of a case study demonstrate that the magnification factor of the proposed system is greater than unity for some cases. Seismic response analysis is conducted for steel moment frames with the proposed vibration control system. Energy dissipation characteristics are examined using the time‐history response results of energy. The maximum story drift angle distributions and time‐history response results of displacement show that the proposed system can reduce the seismic response of the frames effectively. Copyright © 2012 John Wiley & Sons, Ltd.     

Experimental investigation on reparability of an infilled rocking wall frame structure

Improving seismic performance is one of the critical objectives in earthquake engineering. With the development of economy and society, reparability and fast resilience of a structure are becoming increasingly important. Reinforced concrete (RC) frame structure is prone to soft story mechanism. As a result, deformation and damage are so concentrated that reparability is severely hampered. Rocking wall provides an available approach for deformation control in RC frame by introducing a continuous component along the height. Previous researches mostly focus on seismic responses of rocking wall frame structures, while damage mode and reparability have not been investigated in detail. In this study, a novel infilled rocking wall frame (IRWF) structure is proposed. A half‐scaled IRWF model was designed according to Chinese seismic design code. The model was subjected to cyclic pushover testing up to structure drift ratio of 1/50 (amplitude 1/50), and its reparability was evaluated thereafter. Retrofit was implemented by wrapping steel plates and installing friction dampers. The retrofitted model was further loaded up to amplitude 1/30. The IRWF model showed excellent reparability and satisfactory seismic performance on deformation control, damage mode, hysteresis behavior, and beam‐to‐column joint rotation. After retrofitting, capacity of the model was improved by 11% with limited crack distribution. The model did not degrade until amplitude 1/30, due to shear failure in frame beams. The retrofit procedure was proved effective, and reparability of the IRWF model was demonstrated. Seismic resilience tends to be achieved in the proposed system.     

高强钢筋高延性纤维增强混凝土框架结构的屈服机制和抗震性能

为了对混凝土框架结构的地震破坏机制和抗震性能进行控制,在框架柱中配置高强钢筋,并将纤维增强混凝土(FRC)用于框架结构的预期损伤部位。结构柱中的高强钢筋用来减小结构的残余变形,FRC材料用来增加结构的耗能能力和损伤容限。设计了三个框架,采用动力弹塑性时程分析方法进行分析。研究结果表明,采用高强钢筋提高了结构的整体承载能力,在层间侧移角达到3%之前避免了柱铰的出现(包括底层柱底),并且减小了结构的残余变形;预期损伤部位采用FRC材料能够提高结构的塑性耗能。     

基于韧性设计的一种地下框架结构抗震新体系研究

具有功能可快速恢复的抗震结构体系是结构抗震韧性设计的目标,结合浅埋地下框架结构地震破坏和失效模式的震害事例调查与分析以及抗震韧性结构设计的思想,本文提出一种可控制失效模式并具备自复位能力的浅埋地下框架结构抗震新体系。采用数值分析方法研究了传统地下框架结构体系与本文提出的新体系间的抗震能力差异以及新体系的自复位效果。结果表明:与传统的地下框架结构体系相比,新型地下框架结构体系的抗震能力显著提升,并具备良好的自复位能力,实现了结构抗震韧性设计的目标;新体系的自复位效果随轴压比的增加逐渐变差。结合算例,给出了浅埋地下框架结构自复位最大变形能力与轴压比的经验关系。     

框架结构在地震作用下倒塌的离散单元法仿真分析

本文建立了适合框架结构倒塌分析的离散单元模型,并且研究了模型的破坏准则、阻尼等参数确定方法。对框架结构在地震作用下的倒塌全过程进行了数值分析和可视化仿真模拟。算例表明,本文方法是有效的,可以较正确地分析剪切型框架结构的倒塌破坏过程。     

形状记忆合金混凝土框架建筑抗震性能研究

地震作用会造成钢筋混凝土框架发生平面和垂直方向的变形,导致其结构受到更大的地震力,加剧损伤程度。形状记忆合金(SMA)材料在外力作用下能够快速恢复变形前形状,降低框架损伤程度,进一步提高框架结构的承载能力和稳定性。基于此,有必要研究形状记忆合金混凝土框架建筑的抗震性能。以某实际工程为例,采用ANSYS软件建立钢筋混凝土框架有限元模型,选取天津地震波、北岭地震波、印度洋地震波及人工地震波作为地震震动输入,记录地震震动下时程结果。研究结果表明,预应力筋断裂后,该结构在地震作用下的滞回曲线为饱满的旗帜形,最大层间位移为1/125,残余变形在±10 mm之间,最高峰值荷载为211 kN,水平承载力较强,表明其自复位性能较高、地震响应效果较优、抗震承载力较强,可以有效提高建筑结构的安全性和可靠性。     

Centralized semi‐active control of post‐tensioned steel frames

Centralized semi‐active control is a technique for controlling the whole structure using one main computer. Centralized control systems introduce better control for relatively short to medium high structures where the response of any story cannot be separated from the adjacent ones. In this paper, two centralized control approaches are proposed for controlling the seismic response of post‐tensioned (PT) steel frames. The first approach, the stiffness control approach, aims to alter the stiffness of the PT frame so that it avoids large dynamic amplifications due to earthquake excitations. The second approach, deformation regulation control approach, aims at redistributing the demand/strength ratio in order to provide a more uniform distribution of deformations over the height of the structure. The two control approaches were assessed through simulations of the earthquake response of semi‐actively and passively controlled six‐story post‐tensioned steel frames. The results showed that the stiffness control approach is efficient in reducing the frame deformations and internal forces. The deformation regulation control approach was found to be efficient in reducing the frame displacements and generating a more uniform distribution of the inter‐story drifts. These results indicate that centralized semi‐active control can be used to improve the seismic performance of post‐tensioned steel frames. Copyright © 2014 John Wiley & Sons, Ltd.     

装配式混凝土框架结构体系的抗震承载力测试研究

为了提高装配式混凝土框架结构体系的抗震承载力,需要对承载力进行量化测试,提出一种基于弹性模量载荷应力线性评估的装配式混凝土框架结构体系的抗震承载力测试方法。构建装配式混凝土框架结构体系的抗震承载力测试的约束参量模型,结合受力参量估计方法进行应力屈服响应评估,测试装配式混凝土框架结构体系的抗震动态承载力,采用屈服应力推服响应控制方法进行装配式混凝土框架结构体系的抗震承载力的自动加载和自适应控制,测试式混凝土框架结构体系的抗震承载力和抗拉能力,实现混凝土框架结构体系的抗震承载力参数的优化估计。测试结果表明,采用该方法进行装配式混凝土框架结构体系的抗震承载力测试的准确性较高,提高了建筑体的抗震力。     

Response of a 2-story test-bed structure for the seismic evaluation of nonstructural systems

A full-scale, two-story, two-by-one bay, steel braced-frame was subjected to a number of unidirectional ground motions using three shake tables at the UNR-NEES site. The test-bed frame was designed to study the seismic performance of nonstructural systems including steel-framed gypsum partition walls, suspended ceilings and fire sprinkler systems. The frame can be configured to perform as an elastic or inelastic system to generate large floor accelerations or large inter story drift, respectively. In this study, the dynamic performance of the linear and nonlinear test-beds was comprehensively studied. The seismic performance of nonstructural systems installed in the linear and nonlinear test-beds were assessed during extreme excitations. In addition, the dynamic interactions of the test-bed and installed nonstructural systems are investigated.