考虑组合效应的钢框架梁柱节点恢复力模型研究

为了研究考虑节点区组合效应后高层钢框架节点的抗震性能,根据钢框架节点在低周反复荷载作用下足尺模型试验研究成果,总结了各试验节点试件的滞回性能,包括节点的延性、耗能能力等指标.在试验滞回曲线的基础上,考虑试件强度、刚度退化等影响,建立了考虑组合效应的梁柱节点的恢复力模型,所建立的模型可以用于结构弹塑性时程反应分析和钢框架节点抗震设计.     

不同跨高比对多层钢框架内填混凝土深梁结构抗震性能影响

为了研究不同跨高比多层钢框架内填混凝土深梁结构的抗震性能,在钢框架内填混凝土深梁滞回性能试验的基础上,利用ABAQUS对六层纯钢框架（结构一）、钢框架内填跨高比为2混凝土深梁结构（结构二）和钢框架内填跨高比为0.75混凝土深梁结构（结构三）进行弹塑性时程分析。结果表明:内填混凝土深梁使结构整体刚度明显增大;在地震波的作用下,结构二的最大顶点位移降低可达58.3%,结构三的最大顶点位移降低可达89.3%,内填混凝土深梁,结构的抗侧移性能得到了极大改善,且随着深梁跨高比的减小而大幅度提升;结构二滞回曲线饱满,呈现纺锤形,混凝土深梁充分起到了第一道防线作用。经济合理的钢框架内填混凝土深梁结构具有一定的工程应用价值。     

新型型钢-混凝土组合柱恢复力模型研究

提出一种新型型钢-混凝土组合柱,并对其进行数值模拟分析,研究翼缘厚度、钢管径厚比、轴压比、混凝土强度等参数对该组合柱抗震性能的影响。将新型型钢-混凝土组合柱截面进行合理简化,基于平截面假定建立组合柱正截面承载力计算公式,通过对比试验与模拟数据,发现公式计算结果具有较高精度。进一步提出组合柱截面屈服点、峰值点、破坏点、加载刚度、卸载刚度等特征参数的计算方法,确定恢复力模型的滞回规则,最终建立基于退化三线型模型的新型型钢-混凝土组合柱恢复力模型。将公式计算得到的滞回曲线与试验得到的滞回曲线进行对比,发现二者吻合较好。     

基于变轴力柱恢复力模型的钢框筒地震反应分析

建立了考虑轴力变化影响的钢结构杆件的恢复力模型,介绍了模型构成和经试验比较得到的模型的适用性,采用这一模型,对钢框筒结构进行了多维地震作用下的非线性分析,对这类结构的弹塑性特征进行了考察。     

高层高强钢组合偏心支撑框架抗震性能简化分析

高强钢组合偏心支撑钢框架是一种新型的抗震结构体系,为分析其抗震性能,利用ABAQUS有限元软件建立了简化分析模型。在验证该简化模型合理有效的基础上,建立了某十层算例的整体模型,施加竖向荷载的同时施加水平倒三角形循环荷载作用,进而分析了该算例的滞回性能。研究表明:本文提出的简化分析模型不仅可以较准确的模拟该结构体系的延性和抗侧刚度,还可以有效预测结构的变形分布和非线性性能。     

外伸式端板连接型钢-混凝土组合节点恢复力模型研究

通过对7个外伸式端板连接蜂窝钢梁-复合焊接环式箍筋混凝土柱节点组合试件进行低周反复荷载作用下的拟静力试验,分析了不同的螺栓数量、直径以及不同排列方式下节点的抗震性能,建立了该种组合节点的恢复力模型。试验结果表明:螺栓数目多、直径大的试件,抗震性能好;8个螺栓排成四行两列的节点为最合理的节点形式;建议的恢复力模型骨架曲线与试验骨架曲线符合较好,可供外伸式端板连接型钢梁-混凝土柱组合节点组成框架结构的弹塑性地震反应分析参考。     

空间钢框架结构的简化柱梁模型及其弹塑性动力分析

高层钢结构本身构件众多，又要考虑材料非线性几何非线性等因素影响。使得计算非常复杂，这样就非常有必要对其进行简化，多质点系剪切模型在多层平面框架的抗震分析中已得到广泛的应用，但这种模型不能考虑钢框架结构梁柱的强度比和刚度比，节点域变形，柱附加轴力引起的弯曲变形和梁间塑性铰对地震响应的影响。要文介绍的简化柱梁模型考虑以上因素，对高层平面钢框架结构和空间结构进行了有效的简化，并进行了钢框架的二阶弹塑性动力分析。     

钢铅组合防屈曲支撑的滞回性能与参数研究

为简化防屈曲支撑的加工工艺,提高防屈曲支撑的初始刚度和在小变形下的耗能能力,基于现有防屈曲支撑在截面形式与构造方式上的特点,提出了一种新型钢铅组合防屈曲支撑并进行了构造设计。通过有限元数值模拟,分析了钢铅组合防屈曲支撑的耗能特性与效果,建立了恢复力简化模型,并根据理想弹塑性材料本构关系推导出滞回规则。通过对不同设计参数的理论分析和数值模拟,分析了钢铅屈服力比、铅剪切面长宽比、核心段宽厚比和耗能段长度等参数对防屈曲支撑滞回性能的影响。研究结果表明,钢铅组合防屈曲支撑能够提供较大的抗侧刚度,耗能效果良好,加工工艺简单,适合工程应用。     

橡胶垫隔震装置的双向弹塑性恢复力模型

改进了铅芯叠层钢板橡胶垫隔震装置的Park模型，提出其双向弹塑性恢复力模型。建议的模型克服了Park模型不能从橡胶垫力学试验曲线上直观获取所需参数的缺点。采用本文建议模型的结构分析程序HBTA2．0可以方便地用于实际隔震结构的弹塑性动力分析，计算结果也更为合理。     

型钢高性能混凝土剪力墙恢复力模型研究

在前人研究成果的基础上,本文通过对6个型钢高性能混凝土剪力墙荷载-位移滞回曲线的分析,得出了简化的三折线型恢复力模型,并提出各个特征参数的计算公式,计算值与与试验值较为吻合。滞回规则采用考虑刚度退化和强度退化的剪切滞变模型,为型钢混凝土剪力墙的弹塑性分析提供了依据。     

方钢管混凝土柱与钢梁半刚性连接节点的恢复力本构模型

本文在试验研究和有限元模型修正的基础上,对两类方钢管混凝土柱与钢梁半刚性连接节点——缀板连接节点和穿芯螺栓-端板连接节点进行反复荷载作用下的非线性有限元参数分析,结果表明：影响缀板连接节点转动性能的主要因素是缀板的厚度,影响穿芯螺栓-端板连接节点转动性能的主要困索是端板厚度和螺栓直径等。进而通过回归分析建立了上述两类节点弯矩-转角恢复力模型的简化计算公式,可供工程设计与数值简化计算参考。     

轻质砌块填充墙对钢框架地震反应影响分析

本文根据现有的填充墙钢框架结构试验和理论研究成果,提出了一种适用于结构整体分析的框架填充墙有限元模型。采用杆系模型并编制了相应的弹塑性地震反应分析程序。通过对空框架和带填充墙钢框架的地震反应分析,研究了轻质砌块填充墙的存在对钢框架顶层位移反应、底层柱弯矩及柱轴力反应的影响,得出了有益的结论。为进一步完善钢结构抗震设计提供了理论基础。     

Response of infilled frames using pseudo-dynamic experimentation

An accurate and practical testing technique to study seismic performance of multi-storey infilled frames is formulated. This technique is based on the pseudo-dynamic method which can provide an acceptable approximation of the dynamic performance of structures under the influence of earthquake excitation. The pseudo-dynamic experimental technique is outlined and applied for testing a two-bay, two-storey gravity load designed steel frame infilled with unreinforced concrete block masonry walls. From the discussion of the results, the dynamic performance of the tested structure is assessed. © 1998 John Wiley & Sons, Ltd.     

Nonlinear pushover analysis of infilled concrete frames

Six reinforced concrete frames with or without masonry infills were constructed and tested under horizontal cyclic loads. All six frames had identical details in which the transverse reinforcement in columns was provided by rectangular hoops that did not meet current ACI specifications for ductile frames. For comparison purposes, the columns in three of these frames were jacketed by carbon-fiber-reinforced-polymer （CFRP） sheets to avoid possible shear failure. A nonlinear pushover analysis, in which the force-deformation relationships of individual elements were developed based on ACI 318, FEMA 356, and Chen＇s model, was carried out for these frames and compared to test results. Both the failure mechanisms and impact of infills on the behaviors of these frames were examined in the study. Conclusions from the present analysis provide structural engineers with valuable information for evaluation and design of infilled concrete frame building structures.     

On the natural frequencies of infilled frames

Three approximate models are considered for the evaluation of the first few natural frequencies and associated mode shapes of infilled frames, a commonly occurring composite structural system formed by the combination of plane frames and filler walls. The reasonableness of the models is checked with the available experimental results and with the corresponding finite element solutions. The multiple strut model, wherein the infills are replaced by a set of equivalent multiple struts, can account for the frame–infill separation and infill openings and this model is seen to be an improvement over the single equivalent diagonal strut models proposed by earlier investigators. The shear—flexure cantilever analogy, by rationally evaluating the fundamental frequency, aids the equivalent lateral load procedures of the earthquake analysis. For dealing with the frames with central infill openings an equivalent plane frame model is discussed. Besides presenting the approximate models, the effect of frame—infill separation in reducing the fundamental frequency is investigated and an empirical relation is presented in this regard. Also some of the factors influencing the frame—infill contact lengths are studied and this indicates that the contact lengths are highly sensitive and indeterminate. Some constructional methods for avoiding separation and ensuring effective composite action between the frame and infill are also suggested.     

带可替换腹板连接型耗能梁段的恢复力模型研究

带可替换耗能梁段的偏心支撑钢框架具有震后修复方便、经济等优点,但目前国内外学者对该类型的研究很少。为此,设计16组与偏心支撑钢框架采用螺栓连接的腹板连接型耗能梁段,并对16组试件进行数值模拟分析,讨论截面尺寸、耗能长度、加劲肋间距、加劲肋布置以及综合参数等变化参数对腹板连接型耗能梁段在低周往复荷载作用下的滞回性能、骨架曲线的影响,建立腹板连接型耗能梁段简化的恢复力模型。结果表明,影响腹板连接型耗能梁段耗能的主要参数是截面尺寸,建立的恢复力模型与模拟的骨架曲线对比吻合较好,可以为此类耗能梁段弹塑性分析作为参考。     

装配式H型钢柱框架-复合墙结构抗震性能试验研究

提出了一种装配式H型钢柱框架-复合墙抗震结构。为研究结构的抗震性能,进行了1榀足尺装配式H型钢柱框架与1榀足尺装配式H型钢柱框架-复合墙试件的低周反复荷载试验。对比分析了各试件的强度、刚度、延性、滞回特性、耗能能力及破坏特征。研究表明:内嵌复合墙破坏时被分割成多条条型复合墙板,在弹塑性变形后期对框架的支撑作用较为稳定;内嵌复合墙使框架的极限承载力提高了68%,使框架的初始刚度提高了394%;H型钢柱框架-复合墙试件的滞回曲线饱满,未出现捏拢现象;条型复合墙板企口连接的水平条带存在往复咬合错动,对结构耗能能力的提升有明显贡献。     

Implementation and verification of a masonry panel model for nonlinear dynamic analysis of infilled RC frames

The effect of infill panels on the response of RC frames subjected to seismic action is widely recognised and has been subject of numerous experimental investigations, while several attempts to model it analytically have been reported. In this work, the implementation, within a fibre-based Finite Elements program, of a double-strut nonlinear cyclic model for unreinforced masonry panels is carried out. The adequacy of the model in predicting the cyclic/seismic response of multi-storey infilled reinforced concrete frames is then verified through comparisons against experimental results.     

Simplified non‐linear seismic analysis of infilled reinforced concrete frames

The N2 method for simplified non‐linear seismic analysis has been extended in order to make it applicable to infilled reinforced concrete frames. Compared to the simple basic variant of the N2 method, two important differences apply. A multi‐linear idealization of the pushover curve, which takes into account the strength degradation which occurs after the infill fails, has to be made, and specific reduction factors, developed in a companion paper, have to be used for the determination of inelastic spectra. It is shown that the N2 method can also be used for the determination of approximate summarized IDA curves. The proposed method was applied to two test buildings. The results were compared with the results obtained by non‐linear dynamic analyses for three sets of ground motions, and a reasonable accuracy was demonstrated. A similar extension of the N2 method can be made to any structural system, provided that an appropriate specific R–µ–T relation is available. Copyright © 2004 John Wiley & Sons, Ltd.