基于MIDAS的某超限混合结构的静力和动力弹塑性分析

利用MIDAS Building分别对某钢-混凝土混合结构进行7度罕遇地震作用下的静力弹塑性Pushover分析和动力弹塑性时程分析,并对两者的结果进行对比分析,结果表明两种方法结构在罕遇地震作用下的结构地震响应基本趋势相同,结构能够满足"大震不倒"的设防要求,Y向抗震性能优于X向抗震性能,但与静力弹塑性分析相比,动力弹塑性时程分析的塑性铰分布更符合实际情况,因此动力弹塑性时程分析更能反映结构的破坏机制。     

静动力综合法分析结构抗震性能的研究

静力弹塑性分析方法（Push-over分析方法）是一种简化的非线性分析方法,动力弹塑性分析方法是目前公认的一种准确分析方法,本文将二者的优点结合起来,研究了静动力综合法的原理和分析过程。文中首先介绍了退化三线型恢复力模型的基本原理,在此基础上研究了静动力综合法的主要实施过程。然后,对两个混凝土框架结构进行了静动力综合法的分析,并与弹塑性时程分析结果对比,结果表明该方法有较好的精度。     

某高层建筑连体结构的抗震分析

结合现行国家规范、规程,以一实际高层建筑连体结构为背景,采用弹塑性动力时程分析方法对其进行抗震分析,探讨高层建筑连体结构在罕遇地震作用下的动力响应,重点讨论了在罕遇地震作用下结构的侧移、内力及塑性铰的发展变化,并得出了一些有意义的结论。     

广晟国际大厦罕遇地震弹塑性时程分析

采用基于显式积分的弹塑性动力分析方法,对一栋高度约312m超B级高度的超限高层建筑进行了罕遏地震弹塑性时程分析．以了解结构在罕遇地震下的弹塑性行为。结果表明,基于显式积分动力分析法的弹塑性时程分析是保证结构大震不倒的有效方法,本工程采用的框架核心筒结构形式具有较高的抗震承载力和延性．能够满足“大震不倒”的建筑抗震设防目标。     

罕遇地震下高层建筑弹塑性动力时程反应分析

通过对一平面及竖向均不规则且高度超限的高层建筑进行的罕遇地震下动力弹塑性时程分析,评估此类结构在罕遇地震作用下的抗震性能,并对该类建筑抗震设计提出了建议,以期指导高层建筑结构设计。     

复杂高层错层结构的抗震设计

本文结合实际工程，探讨错层复杂高层结构抗震概念设计与分析的有关问题。详细介绍该工程的概念设计，多遇地震的弹性静力分析和弹性动力时程分析结果，罕遇地震的弹塑性动力时程分析和弹塑性静力分析结果，非连续楼板应力分析结果；并提出相应的抗震加强处理措施。     

某超高层剪力墙结构的弹塑性时程分析

某超高层剪力墙结构建筑物主体高度139m、高宽比6.39,属B级高层建筑,平面和竖向布置均不规则。采用通用有限元软件ABAQUS,基于合理的弹塑性材料本构关系模型,对该结构进行了罕遇地震作用下的动力时程分析。通过弹塑性时程分析揭示了结构在罕遇地震作用下的工作性能,本文的有关方法可为相关工程提供参考。     

上海北蔡御桥商业办公项目超限高层结构分析

上海北蔡御桥社区09—01地块商业办公项目的主楼采用框架一核心筒结构，属于平面不规则而竖向规则的超限高层建筑。采用软件SATWE和PMSAP对塔楼上部结构进行了多遇地震作用下的分析，各项指标均满足规范要求；补充了弹性动力时程分析和罕遇地震作用下弹塑性静力分析，结果表明结构具有良好的抗震性能。     

高烈度地区高层建筑错层剪力墙结构抗震性能分析

错层结构对抗震不利。结合一幢高烈度区的钢筋混凝土剪力墙错层高层建筑,采用静力弹塑性推覆分析以及动力弹塑性时程分析方法,研究了结构在设计小震、中震以及大震作用下的变形特征、构件屈服机制及结构破坏模式,揭示出结构中可能存在的抗震薄弱部位,给出了结构在罕遇地震作用下抗震性能的评价,并提出了对同类工程结构设计有益的建议。     

RC框架-剪力墙结构的框架地震层剪力分配

我国《建筑抗震设计规范》与《高层建筑混凝土结构技术规程》关于框架-剪力墙结构地震层剪力分配的规定是依据设计经验提出来的,并没有考虑框架与剪力墙各自抗侧刚度比值的影响,因而较为笼统,明显欠缺合理性。连续化分析方法中框架-剪力墙结构的刚度特征值是表征框架-剪力墙受力和变形的重要指标。本文采用静力弹塑性分析（Pushover）方法和动力弹塑性时程分析方法对刚度特征值为1.0～4.5的8栋框架-剪力墙结构进行了全过程研究,得到了多遇、基本和罕遇地震作用下不同刚度特征值的框剪结构楼层剪力分配,以及罕遇地震下剪力墙刚度退化对楼层剪力分配的影响,并给出了框架层剪力分配公式供设计参考。     

On the applicability of pushover analysis for seismic evaluation of medium‐ and high‐rise buildings

The assumption that the dynamic performance of structures is mainly determined from the corresponding single‐degree‐of‐freedom system in pushover analysis is generally valid for low‐rise structures, where the structural behaviour is dominated by the first vibration mode. However, higher modes of medium‐ and high‐rise structures will have significant effect on the dynamic characteristics. In this paper, the applicability of pushover analysis for seismic evaluation of medium‐to‐high‐rise shear‐wall structures is investigated. The displacements and internal forces of shear wall structures with different heights are determined by nonlinear response history analysis, where the shear walls are considered as multi‐degree‐of‐freedom systems and modelled by fibre elements. The results of the analysis are compared with those from the pushover procedure. It is shown that pushover analysis generally underestimates inter‐storey drifts and rotations, in particular those at upper storeys of buildings, and overestimates the peak roof displacement at inelastic deformation stage. It is shown that neglecting higher mode effects in the analysis will significantly underestimate the shear force and overturning moment. It is suggested that pushover analysis may not be suitable for analysing high‐rise shear‐wall or wall‐frame structures. New procedures of seismic evaluation for shear‐wall and wall‐frame structures based on nonlinear response history analysis should be developed. Copyright © 2009 John Wiley & Sons, Ltd.     

巨型柱倾斜的巨型钢框架结构性能分析

采用大型通用软件ANSYS5.7,以结构的内力、变形和用钢量为指标分析了巨型柱倾斜坡度对巨型钢框架结构静力性能的影响,并对结构下部是截锥体的巨型钢框架与规则的棱柱体巨型钢框架进行了性能对比分析,包括风荷载作用下的几何非线性弹性静力分析和地震荷载作用下的弹塑性时程分析。结果表明将巨型柱倾斜某一坡度可在用钢量相同甚至降低的情况下,明显地提高结构的抗侧刚度和抗震性能。下部是截锥体的巨型框架与规则的棱柱体巨型框架相比,不仅有很好的经济性,而且结构抵抗风荷载和地震荷载作用的能力也有很大提高,是一种优越的超高层建筑结构形式。     

Optimal reduction of inelastic seismic demands in high‐rise reinforced concrete core wall buildings using energy‐dissipating devices

Recently, the issue of large inelastic seismic force demands at severe ground shakings such as maximum considered earthquake level has been highlighted in the conventionally designed high‐rise reinforced concrete core wall buildings. Uncoupled modal response history analysis was used in this study to identify the modes responsible for the large inelastic seismic force demands. The identification of dominant modes and mean elastic design spectra of seven representative ground motions for different damping ratios has led to the identification of three control measures: plastic hinges (PHs), buckling‐restrained braces (BRBs) and fluid viscous dampers (FVDs). The identified control measures were designed to suppress the dominant modes responsible for the large inelastic seismic force demands. A case‐study building was examined in detail. Comparison of the modal as well as the total responses of the case‐study building with and without the control measures shows that all the control measures were effective and able to reduce the inelastic seismic demands. A reduction of 33%, 22% and 27% in the inelastic shear demand at the base and a reduction of 60%, 22% and 26% in the inelastic moment demand at mid‐height were achieved using the PHs, BRBs and FVDs, respectively. Furthermore, a reduction of about 30–40% in the inelastic seismic deformation demands was achieved for the case of the BRBs and FVDs. The study enables us to gain insight to the complex inelastic behavior of high‐rise wall buildings with and without the control measures. Copyright © 2011 John Wiley & Sons, Ltd.     

Prediction of nonlinear seismic demands of high‐rise rocking wall structures using a simplified modal pushover analysis procedure

This study presents a simplified analysis procedure for the convenient estimation of nonlinear seismic demands of high‐rise rocking wall structures. For this purpose, the displacement modification approach used in the nonlinear static procedure of ASCE/SEI 41‐13 is adopted. However, in the current study, this approach is extended to every significant vibration mode of the structure whereas the displacement modifying coefficients for different modes are calculated using the typical flag‐shaped hysteresis behavior of rocking walls. The parameters of this hysteresis behavior are selected to represent rocking walls with a practical range of energy dissipation capacity and postgap‐opening stiffness. The computed peak inelastic‐to‐elastic displacement ratios are presented as mean spectra, which can be used for the convenient estimation of pushover target displacement for every significant vibration mode. The accuracy of proposed procedure is examined using the seismic demands obtained from the nonlinear response history analysis of a 20‐story case study rocking wall structure. Furthermore, a modal decomposition technique is used to determine the individual modal seismic demands. The proposed procedure is found to predict both the combined and the individual modal demands with a reasonable accuracy and can serve as a convenient analysis option for the design and performance evaluation of high‐rise rocking wall systems.     

某复杂高层钢结构静力弹塑性分析及性能评价

利用ETABS对一复杂高层钢结构进行了静力弹塑性pushover分析，对四种加载模式下结构的pushOVer分析结果进行了对比研究。在此基础上，依据我国抗震规范评价了本结构的塑性发展顺序及抗震性能水准。     

Seismic nonlinear static new method of spatial asymmetric multi‐storey reinforced concrete buildings

In order to obtain the seismic demands of spatial asymmetric multi‐storey reinforced concrete (r/c) buildings, a new seismic nonlinear static (pushover) procedure that uses inelastic response acceleration spectra is presented in this paper. The latter makes use of the optimum equivalent nonlinear single degree of freedom system, which is used to represent the general spatial asymmetric multi‐storey r/c building. For each asymmetric multi‐storey building, a total of 12 suitable nonlinear static analyses are needed according to the new proposed procedure, whereas at least 96 suitable nonlinear dynamic analyses are required in the case of nonlinear response history analysis (NLRHA), respectively. In addition, the present paper provides answers to a series of further questions with reference to the spatial action of the two horizontal seismic components in the static nonlinear (pushover) analyses, as well as to the documented calculation of the available behaviour factor of the asymmetric multi‐storey r/c building. According to the paper, this new proposed seismic nonlinear static procedure is a natural extension of the documented equivalent seismic static linear (simplified spectral) method that is recommended by the established contemporary seismic codes, with reference to torsional provisions. Finally, through a restricted parametric analysis carried out in this paper, a relevant numerical example of a two‐storey r/c building is presented for illustration purposes, where the seismic demand floor inelastic displacements are compared with the respective displacements obtained by the NLRHA. Consequently, the new proposed seismic nonlinear static procedure, which uses inelastic response acceleration spectra, can reliably evaluate the extreme values of floor inelastic displacements (on the flexible and stiff side of the building), as is shown by the above comparisons. Copyright © 2010 John Wiley & Sons, Ltd.     

不均匀剪切型层模型结构基于能量概念的弹塑性地震位移反应分析

采用能量概念能更清楚地揭示结构抗震性能的本质。首先介绍了基于能量概念的结构抗震设计有关研究状况。同时根据地震作用下不均匀剪切型层模型结构的弹性和弹塑性时程分析结果,研究了能量在其楼层间分布的特点,给出了楼层能量集中的规律及相关影响因素。并采用等往复振动能量准则建议了能量集中楼层的弹塑性位移计算方法。     

Effect of soft‐storey mechanism caused by infill elimination on displacement demand in nonlinear static procedure using coefficient method

In recent earthquakes, many buildings have been damaged due to the soft‐storey mechanism failure. The seismic design codes for buildings do not contain enough criteria to predict the real displacement of such buildings. This paper focuses on evaluating the nonlinear displacement of buildings that fail in soft‐storey mechanism form. Results show that the nonlinear static procedure with coefficient method, which is described in Chapter 3 of ASCE/SEI 41‐06, does not have sufficient accuracy for estimation of structure displacement demand in such buildings. In this paper, the coefficient methodology is used for evaluating the target displacement for 5‐storey, 8‐storey and 15‐storey special moment resisting steel frames. For this purpose, dynamic nonlinear time‐history analysis has been applied for the mentioned structures having a soft‐storey mechanism failure form. The numerical results of storey displacement and interstorey drift were compared with those values obtained from the coefficient method described in Chapter 3 of ASCE/SEI 41‐06. Copyright © 2012 John Wiley & Sons, Ltd.     

An improved consecutive modal pushover procedure for estimating seismic demands of multi‐storey framed buildings

An improved consecutive modal pushover (ICMP) procedure is proposed to enhance the accuracy of conventional CMP procedure for estimating seismic demands of tall buildings. It accounts for inelastic structural properties and interaction between vibration modes. The displacement increment at the roof of buildings used in each stage of pushover analyses is modified based on the displacement contribution of each mode. The performance of the proposed ICMP procedure is verified against three high‐rise frames subjected to various ground motions. The results obtained from the ICMP procedure are compared with those from the nonlinear time history analysis, conventional pushover analysis, and CMP analysis. The comparison shows the advantages of the ICMP over the other pushover procedures. It is concluded that the ICMP procedure is more accurate than the CMP procedure.