共查询到20条相似文献，搜索用时 156 毫秒
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为了探究能够全面评估钢筋混凝土结构抗震性能的量化指标,借助有限元软件ABAQUS对一拟建的10层框架-剪力墙结构进行了大量的非线性动力时程数值计算,对比分析了不同地震作用下最大层间位移角与滞回耗能的分布情况,从结构滞回耗能的角度揭示了破坏机制,得到主要结论如下:结构层间位移角最大的位置不一定是损伤破坏最严重或者薄弱的部位,以层间位移角作为整体结构抗震性能的判别指标离散性较大,计算结果易受所选地震波的方法及数量影响;结构滞回耗能沿楼层的分布受地震波选取方法和数量的随机性影响较小,结构底层耗能对结构整体耗能贡献最大,约占结构总耗能的60%,其余各楼层滞回耗能约占结构总滞回耗能的1%~8%;梁和柱滞回耗能主要集中于结构底部1层,总的框架梁滞回耗能仅占结构总滞回耗能的18%~22%,绝大部分地震输入能由框架柱吸收,总的框架柱滞回耗能占结构总滞回耗能的80%左右,该计算结果与实际震害中结构主要形成"柱铰"破坏机制的现象较为一致。 相似文献
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基于MPA方法的结构滞回耗能计算 总被引：2，自引：0，他引：2
在能量反应分析中,滞回耗能是最具明确工程意义的而又便于工程应用的能量指标,可用以衡量结构的塑性累积损伤。然而,以往研究中,在计算多自由度体系的滞回耗能时,通常采用时程分析法,计算比较烦杂,不利于工程实际的应用。因此,本文提出了一种采用模态pushover分析（MPA）计算多层结构滞回耗能的简便方法,并通过两个高层结构算例,验证了该方法的精度。结果表明：基于模态pushover分析的结构滞回耗能计算方法精度良好,结果可靠;对于框架结构,可以直接采用第一阶模态（倒三角）加载模式对结构进行pushover分析计算,对于高层框架剪力墙结构,必须组合高阶模态的滞回耗能计算结果。 相似文献
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高层混合结构滞回耗能比的研究 总被引：1，自引：0，他引：1
基于结构层间弯曲屈服强度的概念,提出了高层混合结构滞回耗能比的简化计算公式,该公式综合体现了结构以及地震动特征参数对结构滞同耗能比的影响。研究表明,结构滞回耗能比随地震动的峰值速度与峰值加速度的比值的增大而增大;随着地震动幅值的增大,滞回耗能比也线性增加;对于短持时地震动,滞回耗能比与强震持时之间没有一定的规律性,但对于长持时地震动,结构滞回耗能比会随强震持时的增大而线性增加。随着结构弯曲屈服强度系数的增大,结构滞回耗能比呈凹函数下降,结构的自振周期越大,同一弯曲屈服强度系数对应的滞回耗能比越小;钢框架与混凝土剪力墙承载力比值的增加能够降低结构的滞回耗能比。 相似文献
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《世界地震工程》2017,(2)
为了能够在往复推覆分析中考虑结构能量耗散历程特征的影响,首先根据结构单向耗能能力曲线和耗能需求曲线的交点确定结构在相应地震作用下的延性需求与最大瞬时变形能需求,进而由延性需求得结构的累积滞回耗能需求;其次在已知最大瞬时变形能、累积滞回耗能和能量增长持时的基础上,根据简化模型获得结构变形能耗散历程曲线,该曲线从能量的角度综合体现了地震对结构的峰值效应、累积效应和历程效应,从而实现完全以能量为推覆控制目标的静力非线性分析。研究表明:该往复推覆分析方法能够较为准确的估计钢筋混凝土框架结构在地震作用下的最大层间位移、累积滞回耗能以及滞回耗能在构件中的分布状况。 相似文献
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本文对具有旗帜型滞回模型的单自由度自复位体系提出了设计能量谱的构造方法,包括设计输入能量谱和设计滞回耗能比谱。首先按中国规范场地类别选取360条实际强震记录进行时程分析,对影响单自由度自复位体系输入能量谱和滞回耗能比谱的参数,包括地震波类型、滞回模型、阻尼比、延性系数等进行研究。在此基础上分别建议了设计输入能量谱和设计滞回耗能比谱及其曲线参数的确定方法,并与实际强震记录计算结果进行比较。结果表明结构滞回模型对能量谱影响明显;阻尼比和延性系数对输入能量谱的影响在整个周期范围内有显著差异,但均有明显的削峰作用。建议的两种设计能量谱综合考虑了结构参数、地震波参数和中国场地类别的影响,可以较好的拟合实际情况,并对弹塑性单自由度自复位体系在地震作用下的耗能需求做出较准确的估计。 相似文献
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本文通过能量法研究了钢筋混凝土简体结构的抗震性能。文中采用振型分解法按等效单自由度体系求解简体结构的滞回输入能;用pushover法分析了滞回耗能在结构层间的分布规律及结构自身的耗能能力;根据楼层滞回耗能与弹塑性层间位移的关系求出了薄弱层的弹塑性位移。对一高层钢筋混凝土框架-简体结构在7度罕遇地震下的抗震性能进行了评估,通过与非线性动力时程分析的对比,证明了方法的可行性。 相似文献
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本文通过能量法研究了钢筋混凝土筒体结构的抗震性能。文中采用振型分解法按等效单自由度体系求解筒体结构的滞回输入能;用pushover法分析了滞回耗能在结构层间的分布规律及结构自身的耗能能力;根据楼层滞回耗能与弹塑性层间位移的关系求出了薄弱层的弹塑性位移。对一高层钢筋混凝土框架-筒体结构在7度罕遇地震下的抗震性能进行了评估,通过与非线性动力时程分析的对比,证明了方法的可行性。 相似文献
11.
摩擦摆隔震支座理论分析与数值模拟研究 总被引：5，自引：0，他引：5
介绍了摩擦摆隔震支座的基本构成和隔震原理。利用力学平衡原理,对摩擦摆隔震支座进行了理论分析,推导了摩擦摆隔震支座的刚度和等效粘滞阻尼比,构造了摩擦摆隔震支座的滞回模型,并探讨了该支座的自回复能力,得到了其最大残余位移计算公式。采用有限元软件ABAQUS,对摩擦摆隔震支座进行实体单元建模,模拟低周反复荷载作用下,该支座的滞回特性与回复特性。研究结果表明：①理论分析和数值模拟结果吻合较好,验证了提出的滞回模型和最大残余位移计算公式的正确性;②摩擦摆隔震支座的滞回曲线饱满,具有良好的滞回性能;③摩擦摆隔震支座的刚度与球面半径成反比,可能的最大残余位移为摩擦系数和球面半径的乘积;④该支座的最大应力出现在支座处于设计位移的时刻,且一般位于滑块或支座板球铰面边缘。 相似文献
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考虑场地类别与强震持时的滞回耗能谱的特征分析 总被引：3，自引：0，他引：3
基于力或位移的结构抗震设计方法大多无法反映地震动持时的影响,而能量设计方法则能较好地弥补其不足。按场地类别和强震持时,将302条Northridge地震记录分为15组,对地震记录的峰值进行规一化处理,采用钢筋混凝土退化三线型恢复力模型,对单自由度体系进行弹塑性时程分析,研究场地类别、强震持时、强度屈服水平以及结构周期等因素对滞回耗能的影响。结果表明:在给定地震记录的峰值和屈服强度水平下,结构的滞回耗能依赖于场地条件和强震持时等因素;滞回耗能随强震持时的增加而增大,随场地特征周期的增加而增大。通过非线性回归分析,建立了与峰值加速度、峰值速度、强震持时相对应的简化滞回耗能谱的计算公式。 相似文献
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Non-linear seismic behavior of structures with limited hysteretic energy dissipation capacity 总被引：1，自引：0，他引：1
Pierino Lestuzzi Youssef Belmouden Martin Trueb 《Bulletin of Earthquake Engineering》2007,5(4):549-569
This paper investigates the non-linear seismic behavior of structures such as slender unreinforced masonry shear walls or
precast post-tensioned reinforced concrete elements, which have little hysteretic energy dissipation capacity. Even if this
type of seismic response may be associated with significant deformation capacity, it is usually not considered as an efficient
mechanism to withstand strong earthquakes. The objective of the investigations is to propose values of strength reduction
factors for seismic analysis of such structures. The first part of the study is focused on non-linear single-degree-of-freedom
(SDOF) systems. A parametric study is performed by computing the displacement ductility demand of non-linear SDOF systems
for a set of 164 recorded ground motions selected from the European Strong Motion Database. The parameters investigated are
the natural frequency, the strength reduction factor, the post-yield stiffness ratio, the hysteretic energy dissipation capacity
and the hysteretic behavior model (four different hysteretic models: bilinear self-centring, with limited or without energy
dissipation capacity, modified Takeda and Elastoplastic). Results confirm that the natural frequency has little influence
on the displacement ductility demand if it is below a frequency limit and vice versa. The frequency limit is found to be around
2 Hz for all hysteretic models. Moreover, they show that the other parameters, especially the hysteretic behavior model, have
little influence on the displacement ductility demand. New relationships between the displacement ductility demand and the
strength reduction factor for structures having little hysteretic energy dissipation capacity are proposed. These relationships
are an improvement of the equal displacement rule for the considered hysteretic models. In the second part of the investigation,
the parametric study is extended to multi-degree-of-freedom (MDOF) systems. The investigation shows that the results obtained
for SDOF systems are also valid for MDOF systems. However, the SDOF system overestimates the displacement ductility demand
in comparison to the corresponding MDOF system by approximately 15%. 相似文献
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Stochastic energy analysis of seismic isolated bridges 总被引：1，自引：0，他引：1
In this paper, a parametric stochastic analysis of isolated bridge is proposed with the aim to assess isolation performance and to investigate effects of energetic influence on protection efficiency. The analysis has been carried out in terms of two stochastic parameters of pear-deck maximum displacement and hysteretic energy response, of which a qualitative trend has been observed.Isolated bridge is described by a simple two degree of freedom (TDoF) Bouc–Wen hysteretic model, which has been introduced for its intrinsic ability in reproducing a wide range of real devices behavior. With the aim of taking into consideration intrinsic stochastic nature of seismic events, the ground motion and the structural response have been described by random vibration approach. Results obtained show that protection achieved by shifting structural natural period and reducing input energy by devices dissipation have counteracting effects if related to deck lateral displacement. 相似文献
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Viscous energy dissipators (EDORs) have good suppressing effects on acceleration or base shear and they do not add axial pressure to the column when peak moment in the column occurs at peak displacement. Pall frictional EDORs can dissipate energy even when the compression brace buckles due to a special frictional damping mechanism. Retaining the advantages of viscous and Pall EDORs and overcoming their disadvantages, a pseudo‐viscous frictional energy dissipator (PVEDOR) is developed. PVEDORs use the frictional damping mechanism of Pall EDORs, but the slip force of PVEDORs is made variable so that the slip force reduces with increasing displacement. Behaviour testing of PVEDORs shows that they possess the important hysteretic feature of viscous EDORs, i.e. the restoring force of PVEDORs are out‐of‐phase with displacement. Earthquake simulation tests of a 16‐storey frame structure incorporating PVEDORs and ordinary steel braces and bare frame are carried out. The test results show that PVEDORs have good vibration‐suppressing effects. An analytical hysteretic model of PVEDORs basically agrees with the behaviour testing results. Finally, the parameter influence of PVEDORs on suppressive effectiveness of structural vibration under earthquake conditions is studied. Numerical analyses show that PVEDORs have good control effects on both seismic displacement and acceleration, and that control effects of PVEDORs on base shear are much better than Coulomb‐type frictional EDORs or metallic EDORs. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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结构地震弹塑性反应谱——损伤谱 总被引：1，自引：0，他引：1
首先,本文基于各国广泛使用的由Park和Ang提出的双参数损伤模型,研究基于损伤性能的弹塑性反应谱（损伤谱）的分析方法。其次,文中考虑结构极限状态设计,并通过自编DBDS程序,研究得到了损伤反应谱（简称“RD谱”）,尺。谱综合考虑了结构最大弹塑性位移和结构累积滞回耗能的耦合影响,更加合理地反映结构在罕遇地震作用下的弹塑性行为。第三,通过大量时程分析和拟合得到回归公式及其相关系数,研究成果可供抗震性能评估使用。最后,由本文提倡的RD谱和已有研究的Rμ谱做了定性比较分析,说明了考虑地震动持时的必要性和重要性。 相似文献
17.
Seismic energy dissipation under variable amplitude loading for rectangular RC members in flexure 
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下载免费PDF全文 《地震工程与结构动力学》2018,47(4):831-853
The energy dissipation characteristics of reinforced concrete members that exhibit both strength and stiffness deterioration under imposed displacement reversals were investigated. To do this, 24 symmetrically reinforced concrete rectangular specimens were tested under stable variable and random variable amplitude inelastic displacement cycles. Stable variable amplitude tests were employed to determine the low‐cycle fatigue behavior of specimens where the loading sequence was the major variable. A 2‐parameter fatigue model was developed in order to express the variation of the dissipated energy in displacement cycles with the cumulative hysteretic energy. This model was then used to predict the energy dissipation of test specimens subjected to random variable amplitude displacement cycles simulating severe seismic excitations. It has been demonstrated that the remaining energy dissipation capacity for the next displacement cycle was dependent on the relative relationship between the maximal displacement cycle and the energy dissipated along the completed displacement path. The plastic energy dissipation capacity of reinforced concrete members is both displacement path dependent and cumulative hysteretic energy dependent. 相似文献
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This paper presents qualitative investigations on the energy behaviour of structures into which hysteretic dampers are incorporated. Emphasis was given to the ratio of the structural stiffness after the yielding of hysteretic dampers to the initial elastic stiffness, with a premise that this ratio, termed α in this study, tends to be large for structures with hysteretic dampers. Structures concerned were represented by discrete spring–mass systems having bilinear restoring force behaviour, in which the second stiffness relative to the initial stiffness is α. It was found that with the increase of α the total input energy tends to increase, but the increase is confined to a narrow range of natural periods. Both the total input energy and hysteretic energy were found to become less sensitive to the yield strength with the increase of α. A simple formula was also proposed to estimate the maximum deformation given the knowledge of the hysteretic energy. Analysis of MDOF systems revealed that, even when α is large, the total input energy and hysteretic energy for MDOF systems are approximately the same as those of the equivalent SDOF system, and the hysteretic energy can be distributed uniformly over the stories if α is large. 相似文献
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Hysteretic energy dissipation in a structure during an earthquake is the key factor, besides maximum displacement, related to the amount of damage in it. This energy demand can be accurately computed only through a nonlinear time‐history analysis of the structure subjected to a specific earthquake ground acceleration. However, for multi‐story structures, which are usually modeled as multi‐degree of freedom (MDOF) systems, this analysis becomes computation intensive and time consuming and is not suitable for adopting in seismic design guidelines. An alternative method of estimating hysteretic energy demand on MDOF systems is presented here. The proposed method uses multiple ‘generalized’ or ‘equivalent’ single degree of freedom (ESDOF) systems to estimate hysteretic energy demand on an MDOF system within the context of a ‘modal pushover analysis’. This is a modified version of a previous procedure using a single ESDOF system. Efficiency of the proposed procedure is tested by comparing energy demands based on this method with results from nonlinear dynamic analyses of MDOF systems, as well as estimates based on the previous method, for several ground motion scenarios. Three steel moment frame structures, of 3‐, 9‐, and 20‐story configurations, are selected for this comparison. Bias statistics that show the effectiveness of the proposed method are presented. In addition to being less demanding on the computation time and complexity, the proposed method is also suitable for adopting in design guidelines, as it can use response spectra for hysteretic energy demand estimation. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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结合长联大跨连续梁桥的特点,以1座(65+123+156+123+10×90+55)m长联大跨摩擦摆支座隔震连续梁桥为背景,建立了全桥三维有限元模型,运用非线性时程分析法,分析了地震动输入模式、地震动强度、摩擦摆支座参数对该桥内力、位移和能量响应的影响。研究结果表明:(1)长联大跨连续梁桥布置摩擦摆支座,可有效延滞固定墩顶有效主梁质量效应,实现全桥协同抗震。大部分地震能量可通过支座滞回耗能散耗,大幅降低了该桥固定墩地震能量耗散需求。(2)长联大跨连续梁桥减隔震设计中,建议采用水平单向+竖向地震组合进行内力设计,采用三向地震组合进行位移设计。(3)强震作用下,支座摩擦因数取0.029~0.034时该桥隔震性能最优。 相似文献