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运用SAP2000对普通钢框架和对其进行加腋后的框架进行Pushover分析,得出两类钢框架在多遇和罕遏地震作用下性能点的基底剪力和顶点位移,然后分别以第一次Pushover分析得到的性能点的顶点位移为监测位移再进行Pushover分析,得到多遇和罕遇地震作用下两类钢框架的层位移、层间位移角和各杆件的塑性铰数量及塑性铰出现的顺序。分析结果表明:加腋后钢框架在多遇和罕遇地震下的层位移减小;加腋措施使得钢框架在多遇地震下的层间位移角有减小的趋势,而在罕遏地震下的层间位移角有增大的趋势,但这种影响的幅度不大;加腋措施显著地改善了钢框架在罕遇地震下结构杆件出现的塑性铰数量和塑性铰顺序;加腋后的首层柱底达到极限承载力,为薄弱构件,加腋设计时需要注意。 相似文献
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为研究钢管混凝土加劲环管板节点在轴向拉力作用下的受力性能,开展了3个节点试件的单调加载试验,分别得到了管板节点加强前后的荷载-位移曲线和破坏模式。试验结果表明:SPR节点在单调荷载作用下主管和加劲环发生局部屈曲,表现为延性破坏;CFT节点在荷载作用下主管壁发生剪切破坏,荷载-位移曲线没有明显的屈服段,表现为脆性破坏;CFTR节点在荷载作用下,连接板处加劲环发生剪切破坏,同时加劲环局部V形屈曲;加劲环能够明显提高管板节点的承载力,同时改善节点的塑性性能;相较于主管外设加劲环,主管内部填充混凝土具有更好的承载力提升效果,节点的刚度变大但塑性性能变差;钢管混凝土加劲环管板节点具有加劲环和混凝土的双重特性,在显著提高节点承载力的同时保障节点塑性性能。在264个有限元模型参数分析的基础上,得到了双加劲环管板节点受拉承载力的计算方法,给出了加劲环厚度和宽度组合的设计建议。基于极限分析的塑性铰线方法,推导出SP节点和SPR节点极限承载力的理论计算模型,计算结果与有限元结果吻合较好。 相似文献
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依据现行的《混凝土结构设计规范》(GB 50010—2010)提供的混凝土单轴应力应变曲线,结合能量等价原理,推导出适用于ABAQUS软件计算中混凝土塑性损伤模型损伤因子的计算公式。通过利用ABAQUS软件对文献中一榀2层双跨钢筋混凝土框架进行非线性分析,将框架破坏时的有限元分析结果与文献试验结果进行对比,框架最后破坏现象一致;并将框架有限元分析层间位移结果和文献试验数据进行对比,吻合度较好,从而验证了文中所述混凝土塑性损伤模型中损伤因子的计算公式的可靠性,可为使用ABAQUS软件模拟钢筋混凝土结构在荷载作用下刚度退化提供参数借鉴意义。 相似文献
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《青岛理工大学学报》2017,(4)
为研究腋板加强型节点钢框架在地震荷载作用下抗震性能,分别建立1∶2缩尺比例的腋板加强型节点空间钢框架(SHF)与普通节点空间钢框架(NSF)的ANSYS模型,通过加载罕遇地震波,分析两种节点类型框架在地震荷载作用下层间位移、最大层间位移角、反应加速度和柱底剪力.研究结果表明:腋板加强型节点框架具有明显的梁铰破坏机制,能显著地将梁端塑性铰外移到远离梁柱节点焊缝部位的梁上;腋板加强型节点框架最大层间位移角均小于普通节点框架,在一定程度上限制结构水平位移,避免结构出现较大变形;腋板加强型节点可以减少框架柱底剪力,结构在强震作用下柱脚剪切破坏程度有所降低. 相似文献
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利用MIDAS/Building程序对某双塔连体超限高层建筑结构进行动力弹塑性分析,结合该结构特点从不同角度分别研究结构在实际地震作用下将出现的破坏模式、塑性发展特点等。结果表明,罕遇地震作用下结构最大层间位移角为1/250,满足有关规范规定的限值要求,结构框架柱及连接体未出现破坏,筒体剪力墙底部加强区出现剪切型损伤。整个结构构件塑性铰出现顺序和分布较为合理,满足"大震不倒"的设防要求。 相似文献
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为了探讨钢筋混凝土(RC)梁-钢管混凝土柱框架的抗震性能,进行一榀单跨两层RC梁-钢管混凝土柱框架的拟静力试验,对结构的破坏形态、破坏机制、滞回曲线、骨架曲线、位移延性、刚度退化、耗能能力等性能进行了研究。试验结果表明:RC梁-钢管混凝土柱框架滞回曲线比较饱满;框架在低周反复荷载下,承载力较高,变形能力和耗能能力较强;正向和反向的位移延性系数分别达到9.5和6.8;在反复荷载作用下,框架的水平刚度(割线刚度)随着位移循环次数的增加而降低,模型框架的割线刚度在荷载达到最大后下降变缓;框架的强度随着位移的循环次数的增加降低不大;当梁端出现塑性铰时钢管工作状态良好。 相似文献
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一、研究区域基本现状新疆地处欧亚大陆腹地,地貌轮廓表现为“三山夹两盆”,山地与平原的面积大致各占50%,镶嵌于戈壁沙漠的绿洲仅有7万平方公里。新疆土地面积166.49万平方公里,占全国总面积的六分之一。气候干旱,荒漠广布,是中国最大的干旱区,是亚洲干旱核心区,也是世界上著名的干旱区之一。水资源短缺,生态极度脆弱。新疆2004年底有1950万人,人均GDP已经超过了1000美元,城镇化进入了快速发展阶段,特别是小城镇的发展速度较快。但新疆特殊的干旱区绿洲环境,使得小城镇的发展存在许多问题。一是城镇规模小而散,基础设施配套差,城镇集散和… 相似文献
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Nearly 1500 urine samples were collected from female farmers in eight regions widely scattered in the islands of Japan in the winter of 1987-1988. The samples were analysed for manganese by wet ashing and flameless atomic absorption spectrophotometry under strict quality control. The values observed after adjustment for a specific gravity of 1.016 were distributed log-normally with a geometric mean of 0.65 microgram/l and a geometric standard deviation of 2.47. There was no effect of aging or any effect of smoking on the urinary manganese concentration. The inter-regional difference may be present but not yet conclusive. As no sex difference was observed in a previous study, it may be possible to deduce that the value may possibly stand for the "background" level of both men and women, either smoking or non-smoking, among the general Japanese population. The observed value is discussed in comparison with values reported in the literature. 相似文献
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Although the Dirección de General de Protección Civil (DGPC), an agency of the Spanish government, has been responsible for the collection of data and the statistical analysis of fires since 1985, it has not as yet issued any reports. It is true that a couple of studies have been made, but in neither case did they use a standardized methodology but relied simply on the heterogeneous information provided by the fire brigades which cooperated in the studies. At that time Spanish fire brigades did not have special units for professional fire investigation, nor was the information derived from standardized methodologies suited to research purposes. In addition, information was extremely scarce and basic, focussed only on the fire, the use of the building and personal data of the victims. In this context, the project for a Fire Investigation Unit in the Fire Brigade of Málaga (the sixth largest Spanish province in inhabitants) was set up. Although inspired in the methodologies used in the USA and in the UK, the aim was to create a customized methodology for the first scientific investigation of fires in Spain. Our research was conducted in 2007. Using the methodologies of the USA and the UK, our own methodological approach and the Spanish regulations, we drew up a questionnaire with 110 variables arranged into 6 modules. We studied 96 fires out of the 154 emergency fire calls received in 2007, having omitted some emergency calls for various reasons. Our results revealed that it was necessary to generalize the installation of fire extinguishers in residential buildings, to train the general public in the use of these devices, to promote the use of fire and smoke detectors in residential buildings, to encourage the inspection and control of old electric installations and to monitor the new installations, to generalize the implementation of emergency and evacuation plans and to design new systems and materials for the cabinets where hand-held extinguishers are stored. 相似文献
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介绍了用双硫腙分光光度法测定水中余氯的新方法,阐述了其测定试验过程,根据试验结果显示,其结论符合国家标准,表明该方法可用于自来水等样品中余氯含量的测定,结果比较准确。 相似文献
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目的:花化、香化、彩化已成为城市园林绿化的主要趋势,也是为满足人们对环境要求越来越高的一种心境。方法:选择采用莳花能表现出品种繁多,色彩艳丽等不同的方式,从而能在很大程度上丰富了植物造景的层次感要求。结果:能使其达到美化环境、增添节日气氛、提高绿化品质等方面有着突出的作用。结论:莳花造景对城市的美化可达到立杆见影效果,从而提高城市的形象和品位。 相似文献
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AbstractInequalities relating to ownership of housing have become a major issue de jour in many Western societies. This article examines how the distribution of homeownership in Sweden relates to two factors widely seen as significant to such inequalities, namely parental tenure status and place of birth. We use longitudinal registry data to examine the bearing of these two factors on individual-level tenure progression since the beginning of the 1990s for persons at different stages of their housing careers. We extend existing understandings of Swedish homeownership patterns by demonstrating that inequalities relating to place of birth and parental tenure intersect with one another in ways that substantially advantage certain subgroups while disadvantaging others, and by demonstrating that experiences of entry into homeownership have in recent years been changing in markedly different ways for these different subgroups. Overall, Swedish homeownership inequalities, far from dissipating, appear to be hardening along existing lines. 相似文献
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边坡稳定性的关键问题是确定最危险滑动面(潜在最危险滑动面)和边坡的稳定系数。国内外一般是采用先假定边坡滑移模式,然后近似确定最危险滑动面,再求近似的边坡稳定系数的方法来分析边坡的稳定性,但假设的边坡滑移模式难以反映边坡滑移的实际状态。因此本文探索利用遗传算法搜索最危险滑动面,并得到最小稳定系数及对应的最危险滑动面曲线,取得了较好的效果。 相似文献
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