新型黏滞阻尼墙在某框架-剪力墙结构中的应用

介绍了新型黏滞阻尼墙(VFW)的性能和减震原理,以及附加阻尼比的一种实用计算方法。分别计算了原结构模型、设置VFW的消能器模型以及调整阻尼比的模型三者的地震响应,通过对比设置VFW的模型与调整阻尼比的模型的计算结果,研究消能器为结构提供的附加阻尼比。由分析可知,消能器耗能显著,计算结果满足减震目标要求,消能减震设计方案能够有效改善结构性能,对控制结构层间位移角、减小地震作用具有明显作用。     

澄江化石博物馆振动台试验及能量分析北大核心CSCD

将消能减震技术与基础隔震技术联合应用于澄江化石博物馆结构中,并对该高烈度区复杂钢结构进行了1/30比例模型的模拟振动台试验。研究了该结构的动力特性和地震响应等问题,分析了BRB,推导了能量方程,应用能量原理对该结构的地震输入能、隔震层耗能和上部结构耗能进行了分析,给出了其耗能分布关系。分析结果表明,隔震层耗能占地震输入能的90%左右,减震效果十分明显。     

澄江化石博物馆振动台试验及能量分析

将消能减震技术与基础隔震技术联合应用于澄江化石博物馆结构中,并对该高烈度区复杂钢结构进行了1/30比例模型的模拟振动台试验。研究了该结构的动力特性和地震响应等问题,分析了BRB,推导了能量方程,应用能量原理对该结构的地震输入能、隔震层耗能和上部结构耗能进行了分析,给出了其耗能分布关系。分析结果表明,隔震层耗能占地震输入能的90%左右,减震效果十分明显。     

含不等高箱梁异型节点大型火电主厂房钢框排架结构拟动力试验研究

为研究大型火电厂含异型节点钢框排架主厂房的抗震性能,对缩尺比为1∶10的1 000 MW级火电主厂房钢框排架模型结构进行拟动力试验。输入El Centro波、Taft波和兰州地震波,地震动加速度峰值分别相当于8度多遇地震和7.5、8度设防烈度地震和8、9度罕遇地震,实测了模型结构的应变分布、加速度反应和位移反应。分析了模型结构的滞回特性、加速度放大系数、位移时程曲线以及塑性铰分布。结果表明:含异型节点火电钢框排架主厂房结构总体具有较好的抗震性能,能满足规范"大震不倒"的要求,但由于异型节点处煤斗梁刚度较大且该处承受较大的竖向荷载(煤斗及储煤质量),导致其层间位移分布与无刚度或质量突变的常规钢框架规律不同;异型节点处存在着明显的"强梁弱柱"现象,该类节点大梁底面柱端易产生塑性铰,不利于耗能和抗震。     

某轨道交通上部续建结构减隔震技术的应用

针对某轨道交通续建结构设防烈度从6度提高到7度,现有结构和原设计续建结构已不能满足新规范要求,提出了相应的减隔震措施。采用有限元软件MIDAS Gen进行建模及非线性时程分析,对比了结构加减隔震装置前后在多遇、设防、罕遇地震作用下的层间位移角、楼层剪力等地震响应结果。计算分析了减隔震模型的附加阻尼比、结构整体塑性铰开展情况及铅芯隔震支座与黏滞阻尼器的滞回曲线。结果表明:应用减隔震措施后,结构的周期延长、地震下附加阻尼比增大,层间位移角、楼层剪力等地震响应显著减小并能够满足新规范要求。从结构整体塑性铰开展情况可得:在设防地震下结构刚进入屈服状态,在罕遇地震下结构处于屈服状态且远小于倒塌。由滞回曲线可以看出,铅芯隔震支座与黏滞阻尼器表现出良好的耗能能力,布置合理。为减隔震措施在解决轨道交通续建结构设防烈度提高的问题上提供了成功的工程案例,为续建结构的减隔震提供一定的借鉴参考。     

铅芯消能支撑框架模型结构的试验研究

以山东邹县火电厂钢筋混凝土结构主厂房纵向框架 抗震支撑原型结构为依据 ,以铅芯消能器试验研究为基础 ,首先在钢支撑杆上增设铅芯消能器 ,把原型结构模拟为一个 3层 3跨的平面消能支撑框架模型结构 ,然后对模型结构进行了试验研究 ,并作了简要的理论分析。     

底层柔性柱隔震结构半主动控制研究

为减小隔震结构底部柔弱层的过大变形,提出了一种底层柔性柱隔震结构半主动控制体系。将结构底层柱设计成柔性柱,在底部填充墙与二层梁之间安装磁流变阻尼器,根据主动控制算法来适时调整阻尼器的阻尼力,对结构实施限位和耗能的半主动控制。建立结构振动模型,通过数值模拟分析该体系的振动特点和减震效果。研究表明,这种结构控制体系能有效减小结构的地震反应,隔震层位移减小50%以上,防止结构因底部位移过大而倒塌。隔震层刚度对减震效果有明显影响,层间刚度比应在隔震层位移、层间位移和加速度之间权衡考虑,并保证底层柱在大震下不发生失稳。在没有半主动控制条件的情况下,在隔震层安装固定阻尼耗能器件进行被动控制,也可减小底层位移30%以上。     

竖向不规则高层建筑双层隔震体系的抗扭分析

以某高层竖向不规则框架结构为例,输入双向地震波,采用SAP2000分析罕遇地震作用下基础隔震、层间隔震和双层隔震体系的减震性能。研究表明:双层隔震体系的周期比、顶层加速度峰值和水平向减震系数均最小,层间位移角除在转换层处有突变外,其余各层的层间位移角亦最小。双层隔震体系比单一隔震层体系的支座位移和剪力值都要小很多,滞回曲线更为饱满。双层隔震体系在七层以上位移比都是最小的,因此,对于竖向不规则高层建筑,采用双层隔震体系可有效降低高层结构地震响应和扭转响应,但需要注意局部节点加强。     

底层柔性柱隔震结构半主动控制研究

为减小隔震结构底部柔弱层的过大变形,提出了一种底层柔性柱隔震结构半主动控制体系。将结构底层柱设计成柔性柱,在底部填充墙与二层梁之间安装磁流变阻尼器,根据主动控制算法来适时调整阻尼器的阻尼力,对结构实施限位和耗能的半主动控制。建立结构振动模型,通过数值模拟分析该体系的振动特点和减震效果。研究表明,这种结构控制体系能有效减小结构的地震反应,隔震层位移减小50%以上,防止结构因底部位移过大而倒塌。隔震层刚度对减震效果有明显影响,层间刚度比应在隔震层位移、层间位移和加速度之间权衡考虑,并保证底层柱在大震下不发生失稳。在没有半主动控制条件的情况下,在隔震层安装固定阻尼耗能器件进行被动控制,也可减小底层位移30%以上。     

变摩擦耗能结构在长周期地震作用下动力响应对比分析

变摩擦耗能器能够提供随着位移变化而变化的输出力。描述了三种不同摩擦耗能滞回模型,并对长周期地震波进行了时频对比分析,基于组合概念建立了附设摩擦耗能器的隔震结构模型。分析结果表明:附设摩擦消能器均能够有效减小结构的位移,在长周期地震动作用下,具有哑铃型滞回曲线的摩擦耗能器对结构位移和加速度控制效果最好。     

Seismic retrofit design and risk assessment of an irregular thermal power plant building

Electric power system is one of essential lifeline systems for an urban community. An actual power plant building with typical coal‐fired power generation process is selected to be studied in this paper. The detrimental impacts on the seismic performance of the structural system induced by heavy coal bunkers and irregular bracing configurations are expected to be mitigated by using retrofit strategies. A total of three retrofit design schemes that employ the isolation and supplemental damping techniques are developed. The original design scheme of the actual thermal power plant building that adopts steel special concentrically braced frame as lateral‐force resisting system is used as benchmark for comparison purposes. Nonlinear response‐history analyses are performed, and the obtained seismic responses are compared. To better quantify the benefit of the considered retrofit strategies, seismic risk in terms of probabilities of exceeding designated damage states as well as the downtime are analyzed. For the studied thermal power plant building, the results show that the added damping system is more effective in seismic risk reduction than the isolation for heavy coal bunkers. Compared to the original structural system design, the use of supplemental damping system cut the downtime of the thermal power plant building at most 42%.     

某超高层办公楼结构抗震可恢复性能设计

以一栋超高层办公楼为例,介绍了工程结构的抗震性能目标及耗能装置耗能目标,将可恢复功能防震结构的概念从理论应用到实际工程中。在传统抗震结构布置的基础上,根据结构受力特点布置了BRB、软钢连梁、伸臂阻尼及阻尼墙等耗能装置,并进行了多遇地震作用下的弹性分析和罕遇地震、极罕遇地震作用下的弹塑性分析。多遇地震作用下的弹性分析结果表明,结构主要指标均满足规范要求;罕遇地震作用下的弹塑性分析结果表明,可更换构件及黏滞阻尼构件充分耗能,能够有效地控制结构的残余层间位移角及结构的损伤,结构整体具有良好的震后可恢复性能;极罕遇地震作用下的弹塑性分析结果表明,结构可达到“不倒”的性能目标。     

Seismic resilience design of a super high-rise office building

以一栋超高层办公楼为例，介绍了工程结构的抗震性能目标及耗能装置耗能目标，将可恢复功能防震结构的概念从理论应用到实际工程中。在传统抗震结构布置的基础上，根据结构受力特点布置了BRB、软钢连梁、伸臂阻尼及阻尼墙等耗能装置，并进行了多遇地震作用下的弹性分析和罕遇地震、极罕遇地震作用下的弹塑性分析。多遇地震作用下的弹性分析结果表明，结构主要指标均满足规范要求；罕遇地震作用下的弹塑性分析结果表明，可更换构件及黏滞阻尼构件充分耗能，能够有效地控制结构的残余层间位移角及结构的损伤，结构整体具有良好的震后可恢复性能；极罕遇地震作用下的弹塑性分析结果表明，结构可达到“不倒”的性能目标。     

Simplified optimal design of MDOF structures with negative stiffness amplifying dampers based on effective damping

This paper presents a study on multi‐degree‐of‐freedom (MDOF) structures equipped with a negative stiffness amplifying damper (NSAD). The NSAD not only preserves the negative stiffness feature of negative stiffness devices (NSDs) but also achieves prominent damping magnification effect, substantially reducing a NSD's requirement for high additional damping, which is used to contain the increased displacements resulting from the reduction in overall stiffness of a system. The dynamic equations of MDOF systems with NSADs are described in state–space representation, and the effective damping and frequencies are parametrically studied. Then, a simple optimization method is proposed. A study of the 20‐storey benchmark building shows that NSADs are the most efficient of supplemental devices in reducing interstorey drifts compared with viscous dampers (VDs) and viscoelastic dampers (VEDs) with the same supplemental damping coefficient. For instance, when compared with that of VEDs, the maximal peak interstorey of NSADs can be further reduced by about 30%. In terms of reducing acceleration responses, NSADs perform much better than VDs and VEDs owing to their negative stiffness feature. Partially arranged, NSADs are best implemented at the storeys that have smaller interstorey drift responses. This is because the negative stiffness preserved by NSADs significantly reduces the interstorey drift of storeys without NSADs.     

碟形弹簧竖向减震装置的性能试验研究

基础隔震技术是目前应用最广泛的结构控制方法,但是,目前这种技术只是最大限度地减少或隔离水平地震作用,而对竖向地震作用几乎没有影响。为改善隔震技术在隔离竖向地震中的限制,研制了一种由碟形弹簧和粘弹性阻尼器组合而成的碟形弹簧竖向减震装置,并对其进行了在静载和动载作用下的力学性能试验研究, 给出了该装置在竖向静力和动力作用下的等效刚度和阻尼比,建立了恢复力模型,试验研究表明,碟形弹簧竖向减震装置能有效的解决竖向大承载力和竖向阻尼的难题,力学性能优良且稳定,加工制作容易,是一种比较理想的竖向减震装置。     

低矮砌体结构隔震与非隔震振动台对比试验研究

摘要： 为将橡胶支座隔震技术应用到在我国村镇低矮砌体结构房屋,在室内地坪以上设置隔震层,设计和制作了隔震与非隔震结构模型试件,对其进行振动台对比试验。模型选取未设置构造柱圈梁的两层砖砌体结构,采用1/2的缩尺比例制作。通过对隔震和非隔震结构模型的动力特性、加速度反应、层间位移反应、层间剪力和结构剪重比进行对比分析,研究了低矮砌体结构隔震技术的减震效果,验证了相应构造措施的适用性。振动台试验表明：隔震结构模型在峰值加速度800gal（相当于10度设防）的地震波激励下,没有开裂和破坏,支座复位情况良好;设置隔震层可有效降低结构的自振频率,对加速度、层间位移、基底剪力的减震效果明显,在输入峰值加速度400gal的地震波时,顶层加速度减震率达67%,层间位移减小率为34%,基底剪力减震率达68%;随着地震动强度的增加,隔震结构的减震效果呈增加趋势。研究结果为低矮砌体结构民居隔震技术的应用和相关标准的编制提供参考。     

Multi-objective fuzzy control of smart base isolated spatial structure

Base isolation systems are used widely to reduce the dynamic responses of structures subjected to a seismic load. Recently, research has been conducted actively on smart base isolation systems that can effectively reduce the dynamic responses of isolated structures without accompanying increases in the base drifts. On the other hand, control performance of smart base isolation systems for spatial structures has not attracted significant attention. This study examined the dynamic response reduction capacity of a smart base isolation system for a spatial structure subjected to seismic excitation. MR dampers and low damping elastomeric bearings were used to compose a smart base isolation system, and its vibration control performance was compared with that of the optimally-designed, lead-rubber bearing (LRB) isolation system. A fuzzy controller was used to effectively control the spatial structure with a smart base isolation system. The dynamic responses of the spatial structure with an isolation system conflicted with the base drift. Therefore, these two responses were selected as the objective functions to apply a multi-objective genetic algorithm to optimize a fuzzy controller. The numerical simulation results showed that the smart base isolation system proposed in this study can reduce drastically the base drifts and seismic responses of the example spatial structure compared to the optimally designed LRB isolation system.     

Influence of infill configurations on seismic responses of steel self‐centering moment resisting frames

Steel self‐centering moment resisting frames (SC‐MRFs) have been validated experimentally as resilient structural systems, mainly highlighting the minimized residual drift responses but are prone to suffering high‐mode effects. In this paper, the influence of infill configurations on seismic responses of steel SC‐MRFs was first analyzed. A comparison of the previous experimental results was conducted to investigate the effect of infills on the residual drift of steel frames. In the numerical simulation, the infills were modeled as the equivalent strut diagonals, and the force–displacement of the infills was modeled using the combination of Elastic‐No Tension Material and Hysteretic Material offered by the OpenSees program. The seismic analyses of 3‐ and 9‐story SC‐MRFs with and without infills were carried out to analyze the effects of infills on the residual drift responses and high‐mode contribution under the selected ground motions. Finally, the different infill types and infill irregularities on the seismic responses were investigated to obtain general conclusions. The plastic deformations of columns and infills are also compared in the different cases of infill configurations. The results reveal that all infilled cases experience reduced peak‐story drift and force demands at the upper stories.     

Seismic structural and non-structural performance evaluation of highly damped self-centering and conventional systems

This paper evaluates the seismic structural and non-structural performance of self-centering and conventional structural systems combined with supplemental viscous dampers. For this purpose, a parametric study on the seismic response of highly damped single-degree-of-freedom systems with self-centering flag-shaped or bilinear elastoplastic hysteresis is conducted. Statistical response results are used to evaluate and quantify the effects of supplemental viscous damping, strength ratio and period of vibration on seismic peak displacements, residual displacements and peak total accelerations. Among other findings, it is shown that decreasing the strength of nonlinear systems effectively decreases total accelerations, while added damping increases total accelerations and generally decreases residual displacements. Interestingly, this work shows that in some instances added damping may result in increased residual displacements of bilinear elastoplastic systems. Simple design cases demonstrate how these findings can be considered when designing highly damped structures to reduce structural and non-structural damage.     

Analytical Model for Viscous Wall Dampers

By now, many civil engineering researchers have extensively studied the application of earthquake energy dissipation systems in seismic‐resistant buildings. Earthquake energy dissipation systems play an important role in enhancing the sustainability of structures against seismic excitation. Frame buildings are strengthened by installing damper devices as supplemental structural members. This article presents the finite‐element‐based development of an analytical model for a viscous wall damper (VWD) device, an alternative to other earthquake energy dissipation systems, which can diminish the effect of earthquakes on structures and improve the seismic performance of multistory buildings subjected to ground motion. The constitutive law of VWDs has been formulated and integrated to develop a finite element model of VWD compatible with the reinforced concrete (RC) structure analytical model. Then, the finite element algorithm has been developed for inelastic analysis of RC buildings equipped with VWD devices capable of detecting damage to both structural members and damper connections under dynamic loading. Based on the developed system, the special finite element program was codified and verified by applying it to a real model of a RC building with supplementary VWD devices. Influence of VWDs on seismic performance of the RC building during earthquake excitation was evaluated. The proposed analytical model for VWD is verified by using experimental test data and analysis result proved that this energy dissipation system succeeds by substantially diminishing and dissipating a structure's induced seismic responses. Also the parametric study indicated that the damping coefficient is very effective on performance of VWD.