共查询到19条相似文献，搜索用时 123 毫秒
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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
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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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《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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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。 相似文献
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建立在地震作用下设置阻尼器的基础隔震结构在最大地震响应时刻的能量平衡方程,给出了结构隔震支座和阻尼器的能量表达式,演算了基于能量平衡的设置阻尼器的基础隔震结构的地震响应预测式.选用人工地震波和天然地震波,利用时程分析法的解析值验证了地震响应预测式的精度,比较研究了仅设置粘性阻尼器和同时设置粘性阻尼器和滞回阻尼器的基础隔震结构的抗震性能.研究表明:对于不同的输入地震波,能量法的地震响应预测值包络了多数时程分析的结果,能较好地预测基础隔震结构的地震响应值.在基础隔震结构设计中,建议在隔震层同时设置粘性阻尼器和滞回阻尼器,粘性阻尼器的阻尼比在0.3 ～0.4之间. 相似文献
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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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近年来,能量分析方法在结构抗震设计中的应用问题受到国内外地震工程界的普遍关注,被认为是今后结构抗震设计理论的发展方向之一.以一钢框架-钢筋混凝土剪力墙混合结构为对象,通过逐渐增大框架底层柱截面,分析它们在不同类型地震波下的地震能量反应,结果表明,加强钢框架底层柱使结构总输入能基本不发生变化,结构滞回耗能在总输入能中的比例ν和底部剪力墙滞回耗能占结构总滞回耗能的比例μ均随结构刚度特征值λ的增大而减小,因此,加强钢框架底层柱能够提高外钢框架-内混凝土剪力墙结构体系的抗震能力,降低其在强震作用下的损伤程度. 相似文献
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通过对5种不同支座布置方案的组合基础隔震结构施加不同场地条件下的双向水平地震波,研究了场地类别和地震波加速度峰值及支座布置方式对结构总输入能量的影响,并进行了耗能分析。结果表明,随着地震波峰值的增大,结构总输入能量增大;相同地震峰值条件下,场地土越软,总的输入能量越大;组合隔震结构应用于软土场地时隔震层滞回耗能比更大,隔震效果更好;组合隔震结构两种支座中选择分散布置方案时,隔震层耗能比更大,隔震效果优于支座集中布置方案。 相似文献
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Seismic retrofitting of reinforced concrete frame structures using GFRP-tube-confined-concrete composite braces 总被引：1，自引：1，他引：0
Nasim S.Moghaddasi B 《地震工程与工程振动(英文版)》2012,11(1):91-105
This paper presents a new type of structural bracing intended for seismic retrofitting use in framed structures. This special composite brace,termed glass-fiber-reinforced-polymer(GFRP)-tube-confined-concrete composite brace,is comprised of concrete confined by a GFRP tube and an inner steel core for energy dissipation.Together with a contribution from the GFRP-tube confined concrete,the composite brace shows a substantially increased stiffness to control story drift, which is often a preferred feature in seismic retrofitting.An analysis model is established and implemented in a general finite element analysis program-OpenSees,for simulating the load-displacement behavior of the composite brace.Using this model,a parametric study of the hysteretic behavior(energy dissipation,stiffness,ductility and strength)of the composite brace was conducted under static cyclic loading and it was found that the area ratio of steel core to concrete has the greatest influence among all the parameters considered.To demonstrate the application of the composite brace in seismic retrofitting, a three-story nonductile reinforced concrete(RC)frame structure was retrofitted with the composite braces.Pushover analysis and nonlinear time-history analyses of the retrofitted RC frame structure was performed by employing a suite of 20 strong ground motion earthquake records.The analysis results show that the composite braces can effectively reduce the peak seismic responses of the RC frame structure without significantly increasing the base shear demand. 相似文献
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Seismic performance and damage evaluation of a reinforced concrete frame with hysteretic dampers through shake‐table tests 
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下载免费PDF全文 Passive energy dissipation devices are increasingly implemented in frame structures to improve their performance under seismic loading. Most guidelines for designing this type of system retain the requirements applicable to frames without dampers, and this hinders taking full advantage of the benefits of implementing dampers. Further, assessing the extent of damage suffered by the frame and by the dampers for different levels of seismic hazard is of paramount importance in the framework of performance‐based design. This paper presents an experimental investigation whose objectives are to provide empirical data on the response of reinforced concrete (RC) frames equipped with hysteretic dampers (dynamic response and damage) and to evaluate the need for the frame to form a strong column‐weak beam mechanism and dissipate large amounts of plastic strain energy. To this end, shake‐table tests were conducted on a 2/5‐scale RC frame with hysteretic dampers. The frame was designed only for gravitational loads. The dampers provided lateral strength and stiffness, respectively, three and 12 times greater than those of the frame. The test structure was subjected to a sequence of seismic simulations that represented different levels of seismic hazard. The RC frame showed a performance level of ‘immediate occupancy’, with maximum rotation demands below 20% of the ultimate capacity. The dampers dissipated most of the energy input by the earthquake. It is shown that combining hysteretic dampers with flexible reinforced concrete frames leads to structures with improved seismic performance and that requirements of conventional RC frames (without dampers) can be relieved. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Seismic performance of steel reinforced ultra high-strength concrete composite frame joints 总被引：1，自引：1，他引：0
To investigate the seismic performance of a composite frame comprised of steel reinforced ultra high-strength concrete (SRUHSC)
columns and steel reinforced concrete (SRC) beams, six interior frame joint specimens were designed and tested under low cyclically
lateral load. The effects of the axial load ratio and volumetric stirrup ratio were studied on the characteristics of the
frame joint performance including crack pattern, failure mode, ductility, energy dissipation capacity, strength degradation
and rigidity degradation. It was found that all joint specimens behaved in a ductile manner with flexural-shear failure in
the joint core region while plastic hinges appeared at the beam ends. The ductility and energy absorption capacity of joints
increased as the axial load ratio decreased and the volumetric stirrup ratio increased. The displacement ductility coefficient
and equivalent damping coefficient of the joints fell between the corresponding coefficients of the steel reinforced concrete
(SRC) frame joint and RC frame joint. The axial load ratio and volumetric stirrup ratio have less influence on the strength
degradation and more influence on the stiffness degradation. The stiffness of the joint degrades more significantly for a
low volumetric stirrup ratio and high axial load ratio. The characteristics obtained from the SRUHSC composite frame joint
specimens with better seismic performance may be a useful reference in future engineering applications. 相似文献
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为探究局部锈蚀矩形截面钢筋混凝土（RC）桥墩重度震损加固后的抗震性能,本文对拟静力破坏后的6个矩形截面RC桥墩试件进行扩大截面加固。通过加载试验,对加固桥墩试件从破坏形态、滞回特性、水平承载力、位移延性、侧向刚度以及耗能等方面进行了系统分析。结果表明:相比于普通箍筋,横向施加预应力的改进扩大截面加固方式对破坏后桥墩试件的抗震性能修复成效更佳;在同等位移幅值下,锈蚀率不断增大,桥墩试件抗震性能呈现逐渐降低的趋势;钢筋锈蚀位置上移,加固后桥墩试件的抗震性能提升;轴压比加大,加固后桥墩试件承载力和侧向刚度增大,但延性降低。 相似文献
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钢管混凝土桥墩抗震性能试验研究 总被引：1，自引：0，他引：1
为研究钢管混凝土桥墩的抗震性能,对钢管混凝土桥墩和钢筋混凝土桥墩进行了拟静力对比试验研究。根据试件的破坏发展过程以及各试件的滞回曲线和骨架曲线,分析了其滞回性能、耗能能力、延性、强度退化及刚度退化等抗震性能。试验结果表明,钢管混凝土桥墩的抗震性能明显好于钢筋混凝土桥墩。在含钢率和轴力相同的情况下,钢管混凝土桥墩的滞回曲线比钢筋混凝土桥墩丰满得多,前者的耗能能力约为后者的4.46倍,钢管混凝土桥墩的延性大于钢筋混凝土桥墩;随着轴压比的增大,钢管混凝土桥墩延性有所下降,强度退化加快,但对其刚度退化的影响不大。 相似文献
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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。 相似文献
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Self-centering seismic retrofit scheme for reinforced concrete frame structures: SDOF system study 总被引：1，自引：1，他引：0
This paper presents the results of a parametric study of self-centering seismic retrofit schemes for reinforced concrete (RC) frame buildings. The self-centering retrofit system features flag-shaped hysteresis and minimal residual deformation. For comparison purpose,an alternate seismic retrofit scheme that uses a bilinear-hysteresis retrofit system such as buckling-restrained braces (BRB) is also considered in this paper. The parametric study was carried out in a single-degree-of-freedom (SDOF) system framework since a multi-story building structure may be idealized as an equivalent SDOF system and investigation of the performance of this equivalent SDOF system can provide insight into the seismic response of the multi-story building. A peak-oriented hysteresis model which can consider the strength and stiffness degradation is used to describe the hysteretic behavior of RC structures. The parametric study involves two key parameters -the strength ratio and elastic stiffness ratio between the seismic retrofit system and the original RC frame. An ensemble of 172 earthquake ground motion records scaled to the design basis earthquake in California with a probability of exceedance of 10% in 50 years was constructed for the simulation-based parametric study. The effectiveness of the two seismic retrofit schemes considered in this study is evaluated in terms of peak displacement ratio,peak acceleration ratio,energy dissipation demand ratio and residual displacement ratio between the SDOF systems with and without retrofit. It is found from this parametric study that RC structures retrofitted with the self-centering retrofit scheme (SCRS) can achieve a seismic performance level comparable to the bilinear-hysteresis retrofit scheme (BHRS) in terms of peak displacement and energy dissipation demand ratio while having negligible residual displacement after earthquake. 相似文献