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1.
强震持时对钢筋混凝土结构地震累积破坏的影响   总被引:2,自引:1,他引:2  
本文在计算模型中考虑了钢筋混凝土结构的低周疲劳性能,建立了一种以退化刚度比作为破坏参数的地震破坏评估模型,此模型不仅能够反映大变形破坏,而且也能反映累积损伤效应。在此基础上,文中还研究了强震持时对钢筋混凝土结构累积破坏的影响。结果表明:对于中强长持时地震,低周疲劳效应十分明显地增大了结构的破坏程度,而且强震动持时对结构的累积破坏与结构的非线性变形的低周疲劳效应关系密切。  相似文献   

2.
为了精确地评估强地面运动作用下钢筋混凝土(RC)结构和抗震性能和震害,通常要建立复杂的分析模型,进行三维非线性分析。日本震害减轻研究中心的学者正和加拿大不列颠哥伦比亚大学的学者合作开发可靠的分析模型,以便研究建筑的抗震性能,一种三维非线性动力分析计算机程序正被用于分析结构的地震反应和震害机制。通过考察仪器、记录了建筑物的地震运动反应,验证了分析模型和电算程序的可靠性。本文讨论了电算程序的性能,并且展示了用以建立某个建筑物计算模型的电算模拟技术,对该建筑物计算的地震反应与一次强震中记录结果符合得很好。  相似文献   

3.
钢筋混凝土框架结构地震破坏的计算机模拟方法   总被引:4,自引:1,他引:4  
本文提出了对钢筋混凝土框架结构地震破坏进行计算机模拟的方法,在模拟的过程中,作者建立了破坏单元以及单元破坏准则,导出了切合实际的结构倒塌的判定方法,开发了计算机机动模型的自动生成和分析技术以及可视化模拟技术,为研究钢筋混凝土框架结构破坏过程提供了一个有效的方法。  相似文献   

4.
钢筋混凝土框架地震破坏研究概述   总被引:2,自引:2,他引:2  
关于钢筋混凝土结构的破坏过程,是当前建筑抗震设计与研究中提出的新问题,本文介绍了国内外钢筋混凝土构件非线性地震反应分析和破坏过程研究的进展,和钢筋混凝土框架地震破坏评价的定量描述方法,以及钢筋混凝土框架结构地震破坏过程模拟的最新研究动态,指出地震工程研究领域中研究钢筋混凝土框架结构破坏过程有效手段。  相似文献   

5.
建筑结构地震破坏评估模型   总被引:12,自引:1,他引:12  
  相似文献   

6.
本文对钢筋混凝土框架的地震破坏进行了计算机模拟试验研究,指出了破坏过程中结构瞬态动力特性的变化特征,研究了影响瞬态动力特性的若干因素,明晰了结构整体耗能能力的大小与结构周期的延长之间的关系。作者认为结构瞬态动力特性和地震动的特性是影响结构破坏过程的主要因素,指出结构地震破坏模拟具有广阔的应用前景。  相似文献   

7.
在地震作用下钢筋混凝土建筑结构出现破坏倒塌为地震灾害中的关键,有效评估建筑结构抗地震破坏倒塌能力是建筑结构设计的前提,也是当前建筑结构提高抗震性能与加固的依据。提出变形指标极值、失效判断标准以及钢筋混凝土建筑结构倒塌极限状态判断标准,据此获取倒塌储备系数、倒塌易损性、结构整体超强系数、结构整体延性系数等评估标准。采用Pushover分析法选择相应地震波。依据梁柱线刚比对建筑结构抗倒塌能力的影响,以及柱端弯矩增加系数对建筑结构抗地震破坏倒塌能力的影响,对建筑结构易损性进行分析。结果表明:等跨建筑结构抗地震破坏倒塌能力更强;建筑结构底层是薄弱层,COF值越高,结构越容易倒塌。  相似文献   

8.
9.
工程结构地震破坏概率矩阵分析   总被引:3,自引:0,他引:3  
本文提出了一种计算工程结构地震坡坏概率矩阵的方法,建立了地震地面运动模型和结构分析模型,对结构进行了随机地震反应分析,并获得了结构随机分应的统计量,进而采用双参数的结构破坏模型,给出了教育处结构地震破坏概率的表达式,利用此方法计算了一座按8度要求设计的钢筋混凝土框架型,给出了计算结构地震坡坏概率的表达式,利用此方法计算了一座按8度要求的钢筋混凝土框架结构的地震破坏概率矩阵,本文提出了方法可以在确定抗震设防标准和进行震害预测时采用。  相似文献   

10.
架空管道的地震破坏及其分析方法研究   总被引:1,自引:0,他引:1  
在对高架管道所作震害分析的基础上,通过对实际架空管道脉动和张拉实测结果的分析,从理论和实测角度给出了架空管道的地震反应分析方法及计算模型。  相似文献   

11.
In this paper a rate-dependent isotropic damage model developed for the numerical analysis of concrete dams subjected to seismic excitation is presented. The model is shown to incorporate two features essential for seismic analysis: stiffness degradation and stiffness recovery upon load reversals and strain-rate sensitivity. The issue of mesh objectivity is addressed using the concept of the ‘characteristic length’ of the fracture zone, to show that both the softening modulus and the fluidity parameter must depend on it to provide consistent results as the computational mesh is refined. Some aspects of the numerical implementation of the model are also treated, to show that the model can be easily incorporated in any standard non-linear finite element code. The application of the proposed model to the seismic analysis of a large gravity concrete dam shows that the structural response may vary significantly in terms of the development of damage. The inclusion of rate sensitivity is able to reproduce the experimental observation that the tensile peak strength of concrete can be increased up to 50 percent for the range of strain rates that appear in a structural safety analysis of a dam subjected to severe seismic actions.  相似文献   

12.
A method is presented to quantify the inelastic seismic resistance of reinforced concrete stack-like structures by non-linear earthquake analysis. The deformed configuration of stack is idealized as an assemblage of beam elements and actual stress–strain relationships of concrete and reinforcing steel are used to evaluate element matrices. Repeated non-linear analyses are performed by gradually increasing the intensity of acceleration time histories to a level where collapse of the stack is observed in primary stresses. The set of time histories thus obtained are then used to define the ultimate intensity of ground motion that the stack can sustain if inelastic deformations are permitted. A procedure is presented to quantify the difference between inelastic seismic resistance and elastic seismic resistance in terms of displacement ductility capacity factors. For seismic design using available inelastic resistance, values of curvature ductility factor demand for the cross-sections of stacks are also presented. © 1997 by John Wiley & Sons, Ltd.  相似文献   

13.
A comprehensive, though relatively simple, non-linear method for the seismic damage analysis of reinforced concrete buildings (the N2 method) has been elaborated. The basic features of the method are: the use of two separate mathematical models, application of the response spectrum approach and of the non-linear static analysis, and the choice of a damage model which includes cumulative damage. The method yields results of reasonable accuracy provided that the structure oscillates predominantly in the first mode. Three variants of a seven-storey building have been used as illustrative examples for the application of the method. Four different types of the analysis, with different degrees of sophistication, have been performed in order to estimate the influence of several assumptions and approximations used in the N2 method.  相似文献   

14.
辽西地震重点监视区桥梁震害预测   总被引:1,自引:0,他引:1  
采用统计回归方法,对辽西地震重点监视防御区内4条国家级公路的桥梁133座、4次国有铁路的桥梁331座,以桥梁震害等级划分原则,求取其震害指数、判定震害等级。  相似文献   

15.
将框架结构等效为剪切型模型,采用三线型刚度退化模型,考虑累积损伤效应对结构刚度产生的影响进行结构时程分析,并利用改进的Park-Ang损伤模型计算得到结构的损伤情况。表明结构的第一层损伤最为严重;地震序列不同,引起结构的损伤值也不相同。建议在结构设计的第二个阶段,考虑材料的累积损伤和地震能量吸收与耗散,更能体现出结构的最不利反应状态,有利于制定合理的结构抗震措施。  相似文献   

16.
The optimal design of the members of conventional structures or structures equipped with active bracing systems, known as active structures, is presented for uncertain excitations. Three approaches are used for obtaining the optimal structural design: (1) the time-history analysis of an actual earthquake record (AR), (2) the global energy-bound convex model adjusted with an excitation-specific reduction factor (RGEB), and (3) the global energy-bound convex model adjusted with an average reduction factor (ARGEB) for a set of excitations with common characteristics. The optimal structures obtained using the RGEB and ARGEB convex models have different sizes for their conventional members from the designs based on a time-history analysis of the actual earthquake (AR). The optimal design of the structure is carried out using a modified annealing algorithm. The advantage of using convex models to perform the optimization is that they represent a more general excitation than a single earthquake record. In addition, the RGEB and ARGEB convex models require considerably less computational effort since the constraints of the optimization become time-independent. A comparison between optimal designs of structures with conventional members only, and active structures indicates that the latter are more efficient by combining the conventional and active members.  相似文献   

17.
本文对文献(1 ̄5)提出的液压质量控制系统改进了改进,提出了液压阻尼系统,通过振动台试验研究了其为底层柔性结构的减震控制,揭示了该控制系统的减振机理及其规律。  相似文献   

18.
For the purpose of accurately predicting the seismic response of base-isolated structures, an analytical hysteresis model for elastomeric seismic isolation bearings is proposed. An extensive series of experimental tests of four types of seismic isolation bearings—two types of high-damping rubber bearings, one type of lead-rubber bearing and one type of silicon rubber bearing—was carried out with the objective of fully identifying their mechanical characteristics. The proposed model is capable of well-predicting the mechanical properties of each type of elastomeric bearing into the large strain range. Earthquake simulator tests were also conducted after the loading tests of the individual bearings. In order to show the validity of the proposed model, non-linear dynamic analyses were conducted to simulate the earthquake simulator test results. Good agreement between the experimental and analytical results shows that the model can be an effective numerical tool to predict not only the peak response value but also the force–displacement relationship of the isolators and floor response spectra for isolated structures. © 1997 by John Wiley & Sons, Ltd.  相似文献   

19.
本给出了一种矩形有疬钢筋混凝土蓄水池的震害预测方法和计算分析程序,并对两蓄水池进行了震害预测分析,得出震害经验相符合的结论-地下式水池比地上水池的抗震能力强,从而证明了本方法的实用性。  相似文献   

20.
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