共查询到20条相似文献，搜索用时 0 毫秒
1.
采用Pushover能力谱法对8层钢框架建筑进行基于性能的结构方案设计,考虑偏心支撑钢框架、隅撑支撑钢框架、纯钢框架3种结构体系,对结构自振特性、层间位移角及楼层侧移变化规律、结构刚度及耗能特征以及投资-收益等进行详细对比分析.结果表明:隅撑支撑钢框架和偏心支撑钢框架具有良好的结构性能,同样性能目标下,两者的经济效益相差不大,均可比纯钢框架节省近40%的用钢量,隅撑支撑钢框架的损失期望比例最小. 相似文献
2.
3.
采用Pushover能力谱法对8层钢框架建筑进行基于性能的结构方案设计,考虑偏心支撑钢框架、隅撑支撑钢框架、纯钢框架3种结构体系,对结构自振特性、层间位移角及楼层侧移变化规律、结构刚度及耗能特征以及投资一收益等进行详细对比分析。结果表明:隅撑支撑钢框架和偏心支撑钢框架具有良好的结构性能,同样性能目标下,两者的经济效益相差不大,均可比纯钢框架节省近40%的用钢量,隅撑支撑钢框架的损失期望比例最小。 相似文献
4.
M.R. Shiravand A. Deylami 《The Structural Design of Tall and Special Buildings》2016,25(18):1073-1088
Built‐up and box columns are used extensively in steel structures. A kind of built‐up column is composed of two I rolled shapes separated by calculated interval and welded between two cover plates. The uncertainties due to these columns are the flexibility of the column cover plates under the transferred beam flange plate forces and the brittle behavior of the groove weld between the beam flange plate and the column cover plate. The top and bottom trapezoidal side plates are proposed to improve the behavior of these column moment connections. Using this approach, the total beam flange forces transfer to the lateral sides of the column, parallel to the beam web, by means of top and bottom side plates. An experimental test is developed to study the behavior of the proposed connection under cyclic loading. The results indicate that the proposed connection has sufficient strength and ductility to apply in special moment frames. Also, the rehabilitated connection eliminates the vulnerabilities of deformation of the column cover plate and brittle fracture of groove welds in conventional connections. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
建筑结构基于位移的抗震设计 总被引：63，自引：0，他引：63
简要介绍了国外建筑规范、标准采用基于位移抗震设计的现状 ,介绍了三种分别考虑延性系数、能力谱和位移的基于位移的抗震设计方法 ,讨论了需要研究解决的若干问题 相似文献
6.
Navid Shafiee Mohsen Tehranizadeh 《The Structural Design of Tall and Special Buildings》2015,24(18):1003-1018
Nonlinear static procedures are favored tools for practical applications in the structural engineering profession. However, some limitations are associated with them, including their deficiencies to properly reflect higher modal effects and inertial seismic forces fluctuations in their responses. Some different adaptive pushover methods intended to improve these limitations have been proposed in the literature, but each one has come out with a special deficiency. In this study, based on the concepts of the displacement‐based adaptive pushover, a new dual‐run procedure method called Improved DAP (IDAP) has been developed, aiming to improve higher modal and sign reversal consideration of pushover methods. The seismic scope of this study has been focused on near‐fault regions. Four concrete SMRF with different heights have been employed for the evaluations. The results of the proposed method in terms of capacity curves, interstory and shear profiles are compared with those of the IDA method. Results indicate that the ability of the new method in reproducing seismic story forces and capacity curves, as well as interstory drifts, has been improved in comparison with its primitive counterpart. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
8.
Alireza Tajik Davoudi Reza Abbasnia Abdolreza Sarvghad‐Moghadam Mohammad‐Mahdi Maddah Ali Khodam 《The Structural Design of Tall and Special Buildings》2016,25(7):325-339
The main purpose of the present study is to develop an alternative modal combination rule for use in the adaptive pushover analysis. Since the quadratic modal combination rules do not take into account the sign reversals of the modal load vectors in the higher modes, the accuracy of the advanced pushover methods are decreased. The proposed modal combination rule is a direct vectorial addition technique in which the relative contribution of each mode and its sign are taken into account. The proposed modal combination rule is employed within the displacement‐based adaptive pushover technique, and an alternative pushover procedure is developed. In order to verify the accuracy of the proposed method, two reference buildings are used, and the obtained results from the proposed method and nonlinear time history analysis are compared. It is concluded that the proposed method can estimate the benchmark responses with remarkable accuracy. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
9.
Hong‐Song Hu Rui‐Tao Wang Zi‐Xiong Guo Bahram M. Shahrooz 《The Structural Design of Tall and Special Buildings》2020,29(2)
A generalized method for estimating the drifts of tall buildings composed of planar moment‐resisting frames and coupled shear walls under lateral loading is presented. This method establishes the stiffness equations at the story levels by assuming that all the nodes in the same floor of a planar lateral‐force‐resisting unit have an identical lateral displacement, an identical rotation component due to the axial deformations of the columns, and an identical rotation component due to the flexural and shear deformations of the beams. By adopting this simplification, the story drifts contributed by different types of deformations, namely, the axial deformations of the columns or wall piers, the flexural and shear deformations of the beams, and the double‐curvature bending and shear deformations of the columns or wall piers, can be identified. In the formulation of the stiffness matrix, the P‐Delta effects were also incorporated. Through comparisons between the lateral displacements and story drifts computed using the proposed method and those computed using the structural analysis software Midas/Gen, the proposed method is proved to have high accuracy in estimating the drifts of tall building structures. 相似文献
10.
静力弹塑性分析-基于性能/位移抗震设计的分析工具 总被引：39，自引：0，他引：39
在基于性能/位移的抗震设计研究中,静力弹塑性分析作为计算分析工具越来越受到关注.作者介绍了弹塑性分析在结构抗震设计中的用途,讨论了需要进一步研究的问题.静力弹塑性分析用于日常的工程设计,还有许多配套的研究工作要做. 相似文献
11.
In the present paper, performance‐based design of steel moment‐resisting frames (SMRFs) is implemented to minimize total cost of the structures. The total cost is summation of the initial construction cost and the seismic damage cost in operational lifetime of the structures subjected to seismic loading. In order to evaluate the seismic damage cost, Park–Ang damage index (DI), as one of the most realistic measures of structural seismic damage, is utilized. To calculate the DI, nonlinear time‐history response of the structure needs to be evaluated during the optimization process. As the computational burden of the process is very high, neural network techniques are utilized to predict the required nonlinear time‐history structural responses. As the design constraints, besides the drift checks at immediate occupancy and collapse prevention performance levels, the global DI is also checked at collapse prevention level to control the amount of seismic damage. In order to achieve the optimization task, a sequential enhanced colliding bodies optimization II is proposed. Numerical studies are conducted to demonstrate the efficiency of the proposed methodology involving 2 illustrative examples of a 6‐story SMRF and a 12‐story SMRF. 相似文献
12.
以两个普通六层和十层钢筋混凝土框架结构为例,采用基于纤维模型的逐步增量弹塑性时程方法得到的层间剪力-位移关系曲线,与不同侧力模式的推覆分析结果进行了对比,研究了推覆分析结果的可靠程度。通过与不同场地的大量地震记录的弹塑性时程计算结果进行比较分析,建议采用多种合理的侧力模式进行推覆分析,对结构不同楼层的抗震性能进行全面的评价,即均布侧力模式适合于底部楼层的评价;考虑高度影响分布力模式适合于结构中部楼层的评价;而对结构上部楼层特别是顶层,可以采用SRSS侧力模式或规范侧力模式进行评价。分析研究表明,采用本文建议的侧力模式进行推覆分析,可在统计意义上可对钢筋混凝土规则框架结构的抗震能力作出偏于安全的估计。 相似文献
13.
In this paper, influence of different static condensation methods on nonlinear time history response of structures in presence of full Rayleigh damping matrix has been studied. Equation of motion is derived in details for 2 newly introduced cases; Full Static Condensation Model and Reduced Static Condensation Model (RSCM or RSCM‐1). Nonlinear analyses are performed with state‐space form of equation of motion along with force analogy method. A novel aspect of this study in comparison with previous researches is to consider full Rayleigh damping in formulations for static condensation in nonlinear structural analysis. Numerical examples are presented for the proposed methods. In addition, the same structure was modeled in finite element method and analyzed by the OpenSEES program. Comparisons demonstrate that results, which are obtained from introduced methods in this article, are in good agreement with the finite element method results. In addition to explaining the equation derivations in main article, proofs for some equations have been demonstrated in appendices. The comparisons show that both RSCM and Full Static Condensation Model lead to almost the same results but in case of using RSCM‐1, the responses have some deviation from other condensation methods. 相似文献
14.
Significant effort has gone toward developing accurate and efficient displacement estimation procedures for the nonlinear multi‐degree‐of‐freedom (MDOF) system. Although the dynamic nonlinear analysis is capable of providing the high computational precision through the step‐by‐step time integration method, the simplified method is still expected and imperative for seismic design practices. The work presented in this paper focuses on the implementation of using the modal superposition method to estimate displacement responses of the nonlinear MDOF system based on the force analogy method (FAM). The current research demonstrated that the equation of motion for the nonlinear MDOF system can be decoupled, but other two governing equations in the FAM about the internal force, such as the moment and force of structural members, are not decomposable. Thus, the FAM is incorporated with the modal pushover analysis (MPA) method to determine the basic parameters of each mode such that the modal superposition method can be suitable for the solution of the nonlinear MDOF system. The procedure presented here is an approximately estimation method due to the application of MPA method. However, the value and potential for the maximum displacement estimation of the nonlinear MDOF system were demonstrated through the application in a framed structure. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
15.
针对拟力法仅在刚性连接钢框架中应用的现状,根据钢筋混凝土框架以及半刚性连接钢框架的受力特点,并基于拟力法的基本假定与思路,得出了钢筋混凝土结构中塑性铰和半刚性连接钢框架中连接的弯矩-相对转角关系,从而推导并获得了拟力法在框架结构静力弹塑性分析中的通用公式。通过与有限元理论计算结果的比较,表明基于拟力法的框架结构静力弹塑性分析方法在应用于各类框架结构时都有着较高的精度,从而为将基于拟力法的动力弹塑性分析包括地震能量分析拓展到钢筋混凝土框架结构以及半刚性连接钢框架结构中奠定了基础。 相似文献
16.
The determination of the fundamental period of vibration of a structure is essential to earthquake design. Current code equations such as American Society of Civil Engineers Standard (ASCE) 7‐10 provide formulas for the approximate period of moment‐resisting frames (MRFs), which are dependent only on the height of the structure or number of stories. Such a formulation is overly conservative and unable to account for structures with geometric irregularities. This study investigated the fundamental periods of MRFs with varying geometric irregularities. The fundamental periods based on vibration theory for each example were compared with empirical equations, including current code equations as well as equations proposed in recent literature. New equations are proposed for the fundamental periods of MRFs, which take into account vertical and horizontal irregularities. Through statistical comparison, it was found that a three‐variable power model that is able to account for irregularities resulted in a better fit to the Rayleigh data than equations that were dependent on height only. The proposed equations were validated through a comparison of available measured period data for MRFs. They will allow design engineers to quickly estimate the fundamental period of MRF structures by taking into account irregularities. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
17.
Onur Şeker Bulent Akbas Jay Shen A. Zafer Ozturk 《The Structural Design of Tall and Special Buildings》2014,23(12):897-928
Steel moment‐resisting frames (SMRFs) are the most common type of structural systems used in steel structures. The first step of structural design for SMRFs starts with the selection of the structural sections on the basis of story drift limitation. ASCE 7 (2010) requires that the inelastic story drifts be obtained by multiplying the deflections determined by elastic analysis under design earthquake forces with a deflection amplification factor (Cd). For special moment‐resisting frames, Cd is given as 5.5 in ASCE 7 (2010). Lower Cd values will increase the overall inelastic response of the structure. On the other hand, the inelastic response of the structure is expected to be less severe when designed for higher Cd values. The performance objective is that the structure should sustain the inelastic deformation demand imposed due to design earthquake ground motions. This study aims at investigating the inelastic seismic response that low‐rise, medium‐rise and high‐rise SMRFs can experience under design earthquake ground motions and maximum considered earthquake (MCE) level ground motions and evaluating the deflection amplification factors (Cd) for SMRFs in a rational way. For this purpose, nonlinear dynamic time history and pushover analyses will be carried out on SMRFs with 4, 9 and 20 stories. The results indicate that the current practice for computing the inelastic story drifts for SMRFs is rational and the frames designed complying with the current code requirements can sustain the inelastic deformations imposed during design earthquake ground motions when seismically designed and detailed. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
18.
A bottom flange friction device (BFFD) has been developed as an energy dissipation device for self-centering post-tensioned steel beam-to-column connections for moment-resisting frames (MRFs). The BFFD is located beneath the beam to avoid interference with a floor slab. Since the BFFD is attached to only one flange, a connection with a BFFD has an asymmetric behavior with different positive and negative moment capacities. To investigate the behavior of a self-centering MRF with BFFDs, static and dynamic analyses were performed, and the results were compared to those of a similar frame with connections that have a symmetric behavior. It was found that the asymmetric behavior of the MRF with BFFDs leads to increased inelastic strain in the beam top flange, which may lead to beam flange buckling. These inelastic strains can be reduced by using longer top flange reinforcing plates. 相似文献
19.
楼梯系统对于框架抗震性能的影响 总被引：9，自引：0，他引：9
为研究楼梯构件对框架结构抗震性能的影响,建立了考虑楼梯构件的精确分析模型,首先对弹性分析的结果进行了对比分析;进一步的Pushover分析结果表明：考虑楼梯构件的框架结构在强震作用下塑性变形机制与常规的框架计算模型有较大的差别。最后．文章给出了考虑偻梯构件影响的抗震框架结构的设计建议。 相似文献
20.
It is known to be a necessary practice to study the effect of infill walls on fundamental period and revise the equations included in the current building codes. In this research, the fundamental period of vibration, by modeling an infill wall as a compression strut in three‐dimensional numerical models of moment‐resisting steel frames, was studied. Areas studied in the present research were structures of symmetric infill wall arrangements wherein the effects of various infill percentage, various moduli of elasticity of masonry wall materials, and different numbers of spans were investigated. The mean fundamental period obtained by the formula provided in FEMA450 was 1.3 times greater than the value resulted from the numerical modeling of infilled moment‐resisting steel frames. Moreover, the corresponding coefficient of determination, R2, of the curve fitted to numerically obtained periods was found to be 0.65 when the fundamental period of the infilled frames was only estimated based on the height of buildings, indicating a great deal of variation within the results. A new formula was proposed to estimate the fundamental period based on the structure height, infill wall percentage, and modulus of elasticity, at an acceptable level of accuracy so that the R2 coefficient was determined to be 0.99 for the results of the proposed formula. 相似文献