形状记忆合金(SMA)被动耗能减震体系的设计及参数分析

本文探讨了基于形状记忆合金超弹性特性的被动耗能减震体系的设计方法,编制了形状记忆合金被动耗能减震体系在大震下的弹塑性反应分析程序.采用该程序,分析了SMA耗能装置的设计参数对结构地震反应的影响,给出了参数的合理取值范围.最后,还讨论了SMA被动耗能装置的布置方式对多自由度结构减震效果的影响.     

振戎中学食堂楼耗能减震分析与设计(Ⅰ)－反应谱法

本文采用耗能减震技术，根据建筑结构抗震规范规定的反应谱法，利用CTAB程序对云南省洱源县振戎中学食堂进行了抗震计算分析和设计验算。首先对未加耗能减震装置的空框架结构进行了小震下的位移和强度验算以及大震下的位移验算；其次，介绍了本工程选用的T字芯板摩擦耗能器的工作原理，并对耗能器进行了足尺性能试验；第三，根据工程结构的环境特点和建筑使用功能要求，确定了耗能减震方案；最后，对耗能减震结构进行了抗震验算和分析，结果表明，附加耗能器后的工程结构抗震性能得到了明显改善。     

振戎中学食堂楼耗能减震分析与设计(Ⅰ)一反应谱法

本文采用耗能减震技术，根据建筑结构抗震规范规定的反应谱法，利用ＣＴＡＢ程序对云南省洱源县振戎中学食堂进行了抗震计算分析和设计验算．首先对未加耗能减震装置的空框架结构进行了小震下的位移和强度验算以及大震下的位移验算；其次，介绍了本工程选用的Ｔ字芯板摩擦耗能器的工作原理，并对耗能器进行了足尺性能试验；第三，根据工程结构的环境特点和建筑使用功能要求，确定了耗能减震方案；最后，对耗能减震结构进行了抗震验算和分析，结果表明，附加耗能器后的工程结构抗震性能得到了明显改善．     

振戎中学食堂楼耗能减震分析与设计（I）—反应谱法

本文采用耗能减震技术，根据建筑结构抗震规范定的应用谱法，利用CTAB程序对云南省洱源县振戎中学食堂进行了抗震计算分析和设计验算，首先对未加耗能减震装置的空框架结构进行了小震下的位移和强度验算以及大震下的位移验算，其次，介绍了本工程选用的T字芯板摩擦耗能器的工作原理，并对耗能器进行了足尺性试验，第三，根据工程结构的环境特点和建筑使用功能要求，确定了耗能减震方案，最后，对耗能减震结构进行了抗震验算和分析，结果表明，附加耗能器后的工程结构抗震性能得到了明显改善。     

可控消能减震原理及结构分析

本文介绍一种新的减震结构体系及其分析方法。这种结构体系的减震系统由控制装置及耗能装置组成，控制装置根据结构反馈的相关信号，在回头点处启动耗能装置，耗散大量地震能量，属于半主动控制范畴。试验及理论分析表明，这种结构体系的减震效果良好，能够将结构的地震位移反应降低５０％以上。本文介绍了这种结构体系的减震工作原理、数学模型、理论分析方法及算例，并给出了相应的结论。     

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。     

基于正交设计的粘弹性阻尼器参数优化

粘弹性阻尼器耗能能力受其剪切储存模量、剪切损失模量、剪切面积、粘弹性层厚度等多种参数的影响.为了探讨耗能器的减震控制效果,将现代振动控制理论和正交设计相结合,以结构顶层各点的最大位移和最大加速度为评价指标,在不同的参数水平下对某5层框架结构进行动态仿真,并给出各种参数对结构振动控制的贡献.计算结果表明,粘弹性阻尼器可以有效地控制框架结构的地震响应,选择合适的材料参数,位移峰值衰减可高达90.8%,加速度峰值衰减可高达63.8%.     

考虑轨道约束的连续梁拱桥地震反应及减震控制研究

以一座大跨度单线铁路连续梁拱桥为背景,建立了考虑轨道约束和相邻构件碰撞效应的动力分析模型;通过输入40组水平双向地震动记录进行非线性时程分析,探究轨道约束和拱肋对桥梁地震响应的影响,采用"减震榫-拉索限位器"与"自恢复耗能支撑(SCEDB)-屈曲约束支撑(BRB)"控制水平向地震反应,并对比两种组合减震控制系统的减震效...     

某耗能减震框肢剪力墙转换结构分析

采用复合型铅粘弹性阻尼器对带转换层框肢剪力墙结构的某酒店进行了耗能减震设计,对耗能减震结构和钢支撑结构进行了对比分析,包括反应谱和局部非线性多遇地震作用和罕遇地震作用下的时程分析。结果表明,底部框架结构布置复合型铅粘弹性阻尼器后,在多遇和罕遇地震情况下层间位移能满足《建筑抗震设计规范》要求,并且采用耗能减震结构能优化整体结构,不会对转换层上部结构产生不利的影响,能更好地改善结构的抗震性能。     

粘滞阻尼减震结构抗震可靠度简化分析

通过设置粘滞阻尼器减小结构的地震反应是一种有效的被动控制方式,为与现行抗震设计水平相适应,减震结构和控制装置的设计也应该以可靠度为基础。本文结合粘滞阻尼减震结构的受力特性建立了此类耗能减震结构动力可靠度分析的实用简化计算方法。首先通过等价线性化方法,给出了层间三线型恢复力模型的等效平均刚度,粘滞阻尼器采用等效线性化的力学模型,建立了安装粘滞阻尼减震结构的等效线性随机分析模型。然后采用随机状态空间方法进行了粘滞阻尼减震结构的地震反应分析,基于层间变形失效准则和首次超越理论分析了粘滞阻尼减震结构的可靠度,并以粘滞流体阻尼器的变形超过其自身极限变形作为阻尼器的失效模式,讨论了粘滞阻尼器可靠度的计算。最后通过一个设置粘滞流体阻尼器的框架结构计算实例,说明了这种方法的运用。该方法可以作为一种实用的方法对振动控制结构在不同破坏状态下的抗震可靠度进行分析,为基于性能的抗震设计和优化提供参考。     

公路简支梁桥的地震能量响应分析

利用有限元软件SAP2000建立了某公路简支梁桥的有限元模型,以7条典型强震记录为输入,研究了公路简支梁桥的地震能量响应及其分配规律。结果表明:①地基柔性效应对公路简支梁桥的地震能量响应及其分配规律的影响较小;②当场地土质变软时,地震总输入能、结构阻尼耗能和结构阻尼耗能比均呈递增趋势,而结构滞回耗能和结构滞回耗能比则不断减小,即地基土体作为桥梁动力系统的一部分,增大了系统阻尼,并分担了部分非弹性变形;③随着PGA增大,输入结构的地震能量也增加,导致塑性铰的非弹性变形增加,即结构滞回耗能和结构阻尼耗能增大。     

Seismic energy dissipation for cable-stayed bridges using passive devices

This study assesses analytically the effectiveness, feasibility and limitations of elastic and hysteretic damping augmentation devices, such as elastomeric and lead–rubber bearings, with respect to the dynamic and seismic performance of cable-stayed bridges. This type of bridge, which has relatively greater flexibility, is more susceptible to undesirable vibrations due to service and environmental loadings than are conventional bridges. Therefore, damping is a very important property. Supplementary damping devices based on the plastic deformation of lead and steel are proposed at critical zones, such as the deck–abutment and deck–tower connections, to concentrate hysteretic behaviour in these specially designed energy absorbers. Inelastic behaviour in primary structural elements of the bridge can therefore be avoided, assuring the serviceability of these cable-supported bridges. Analytically, three-dimensional modelling is developed for the bridge and the damping devices, including the bridge geometrical large-displacement non-linearity and the local material and geometric non-linearities of the energy dissipation devices. The effects of various modelling and design parameters of the bridge response are also studied, including the properties, modelling accuracy and location of the devices along the bridge superstructure. It is shown that an optimum model of the seismic performance of the bridges with these passive control devices can be obtained by balancing the reduction in forces along the bridge against tolerable displacements. Appropriate locations and hysteretic energy dissipation properties of the devices can achieve a significant reduction in seismic-induced forces, as compared to the case with no dampers added, and relatively better control of displacements. In addition, proper selection of the location of the passive control systems can help redistribute forces along the structure which may provide solutions for retrofitting some existing bridges. However, caution should be exercised in simulating the device response for a reliable bridge structural performance. Moreover, while seismic response of the bridge can be significantly improved with added dampers, their degree of effectiveness also depends on the energy absorption characteristics of the dampers.     

波形钢腹板混凝土箱拱地震响应分析

采用时程分析法,对三向地震动作用下的波形钢腹板混凝土箱拱新型结构的地震特性进行分析,通过与混凝土腹板的混凝土箱拱动力特性和地震响应特点的对比,得出该新型拱圈结构具有较优越的抗震性能。同时,把三向地震作用的结果与在两个主方向(纵桥向和横桥向)同时施加地震动的计算结果进行比较,得到竖向地震动对波形板箱拱地震响应的影响程度。     

Fuzzy logic control of bridge structures using intelligent semi-active seismic isolation systems

Passive supplemental damping in a seismically isolated structure provides the necessary energy dissipation to limit the isolation system displacement. However, damper forces can become quite large as the passive damping level is increased, resulting in the requirement to transfer large forces at the damper connections to the structure which may be particularly difficult to accommodate in retrofit applications. One method to limit the level of damping force while simultaneously controlling the isolation system displacement is to utilize an intelligent hybrid isolation system containing semi-active dampers in which the damping coeffic ient can be modulated. The effectiveness of such a hybrid seismic isolation system for earthquake hazard mitigation is investigated in this paper. The system is examined through an analytical and computational study of the seismic response of a bridge structure containing a hybrid isolation system consisting of elastomeric bearings and semi-active dampers. Control algorithms for operation of the semi-active dampers are developed based on fuzzy logic control theory. Practical limits on the response of the isolation system are considered and utilized in the evaluation of the control algorithms. The results of the study show that both passive and semi-active hybrid seismic isolation systems consisting of combined base isolation bearings and supplemental energy dissipation devices can be beneficial in reducing the seismic response of structures. These hybrid systems may prevent or significantly reduce structural damage during a seismic event. Furthermore, it is shown that intelligent semi-active seismic isolation systems are capable of controlling the peak deck displacement of bridges, and thus reducing the required length of expansion joints, while simultaneously limiting peak damper forces. Copyright © 1999 John Wiley & Sons, Ltd.     

多点激励下拱桥竖向地震反应的简化计算方法

以某大跨公路拱桥为例,通过对拱桥在三种行波输入模式下地震反应的对比计算,提出了拱脚行波输入的简化输入方式;利用拱桥结构的对称性特点,提出了多点输入下半拱叠加的简化计算方法。经验证,这一计算方法具有良好的计算精度,可将较为复杂的拱桥多点输入地震反应计算问题,转化为工程技术人员熟悉的一致输入下地震反应计算问题。     

大跨径钢管混凝土拱桥减震控制装置参数的研究

大跨度桥梁结构的减震控制研究对于桥梁结构的抗震安全具有重要意义。本文以主跨368m的茅草街大桥为研究对象,基于ANSYS建立了该桥的三维有限元模型,并采用子空间迭代法分析了该桥的动力特性。在此基础上进行了大跨度钢管混凝土拱桥的地震响应及减震控制研究,重点进行了弹性连接装置和粘滞阻尼器减震效果的参数敏感性分析,并对比分析了不同位置布设减震装置时的效果。结果表明,纵飘振型对该桥肋纵向相对位移的贡献最大;弹性连接装置和阻尼器均能有效减小地震作用下该桥的肋梁纵向相对位移;综合考虑各关键部位的地震响应时,同时采用两类减震装置并将其分散布置时的减震效果最佳。结论可供大跨度中承式钢管混凝土系杆拱桥的抗震设计参考。     

行波效应对桥梁不同振动控制方法减震效果的影响分析

给出了地震行波输入下大跨度桥梁的主动、半主动和被动控制分析方法,并对1座4跨连续刚构桥梁进行了行波输入下地震反应计算,分析了8种振动控制情况下纵桥向和横桥向地震反应的减震效果。结果表明,行波效应会明显降低该连续刚构桥梁8种振动控制方法的纵桥向地震反应减震效果,最大开关控制算法对纵桥向的减震效果相对最好;最大阻尼力被动控制和最大开关控制算法对横桥向的减震效果相对最好,采用该2种控制方法时行波效应对横桥向总体减震效果影响不大。     

强震下拱式体系桥梁震害特征及抗震研究

以汶川地震中拱式体系桥梁震害为主线,总结主拱圈、横向连接系和其它附属构件及减隔震设计拱桥的破坏情况,对国内外拱桥的震害特征及原因进行了剖析。以目前应用数量占优的钢管混凝土肋拱桥为具体背景,对拱式体系桥梁的抗震理论、抗震试验和减隔震设计进行了评述。分析认为拱式体系桥梁竖向和纵桥向抗震存在一定的安全储备,但横桥向存在明显的抗震薄弱环节。针对钢管混凝土肋拱桥横桥向振动及倒塌特点,就目前在拱式体系桥梁中引入防屈曲支撑代替横撑以形成耗能减震结构提出了建议及具体可行设计方式。     

Modeling of energy dissipation in structural devices and foundation soil during seismic loading

Though rocking shallow foundations could be designed to possess many desirable characteristics such as energy dissipation, isolation, and self-centering, current seismic design codes often avoid nonlinear behavior of soil and energy dissipation beneath foundations. This paper compares the effectiveness of energy dissipation in foundation soil (during rocking) with the effectiveness of structural energy dissipation devices during seismic loading. Numerical simulations were carried out to systematically study the seismic energy dissipation in structural elements and passive controlled energy dissipation devices inserted into the structure. The numerical model was validated using shaking table experimental results on model frame structures with and without energy dissipation devices. The energy dissipation in the structure, drift ratio, and the force and displacement demands on the structure are compared with energy dissipation characteristics of rocking shallow foundations as observed in centrifuge experiments, where shallow foundations were allowed to rock on dry sandy soil stratum during dynamic loading. For the structures with energy dissipating devices, about 70–90% of the seismic input energy is dissipated by energy dissipating devices, while foundation rocking dissipates about 30–90% of the total seismic input energy in foundation soil (depending on the static factor of safety). Results indicate that, if properly designed (with reliable capacity and tolerable settlements), adverse effects of foundation rocking can be minimized, while taking advantage of the favorable features of foundation rocking and hence they can be used as efficient and economical seismic energy dissipation mechanisms in buildings and bridges.