首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 640 毫秒
1.
孙潇 《科技通报》2019,35(3):172-176
伴随经济快速发展城市化进程推进加速,高层建筑逐渐增多,提供给人们舒适环境时建筑结构抗震性能也受到人们重视。文中将高层联体式建筑作为研究对象,进行抗震弹塑性最大响应值研究。运用Push-over分析法(推覆分析法)先对联体式建筑结构行为进行分析,在水平作用力条件下估测结构构件从进入弹性到崩塌过程;对建筑结构抗震承载力进行分析,获知结构抵抗侧向力水平,能否达到建筑结构承载力设计要求;通过该分析法得到建筑结构整体位移和局部构建间形态变化关系。采用时频反应谱分析法研究地震情况下建筑结构累积破坏效应及破坏机理,根据反应谱定义,分析地震动时结构时频特征和建筑结构动力特征,获得弹塑性时频反应谱值,最终得到弹塑性体系的运动固定频率及固定频率的质点结构在地震作用下最大响应值。实验证明,通过对结构弹塑性分析满足了高层建筑抗震设计需求。  相似文献   

2.
本文通过有限元分析程序ABAQUS对一足尺三层钢框架-支撑结构进行动力弹塑性分析。将模拟分析结果与振动台试验结果进行对比,结果显示该数值模拟方法能很好地反映结构的弹塑性行为及破坏机制,准确预测结构的地震响应。利用ABAQUS/Explicit有限元程序以及梁元(B32)方法进行钢框架-中心支撑结构弹塑性时程分析是可行的;同时,论证ABAQUS中参数是合理的。  相似文献   

3.
研究线性荷载下混凝土梁抗拉强度幂值函数预测模型,对筋混凝土柱的拟静力试验进行模拟分布,构建钢筋混凝土柱状结构下的应力损伤模型,实现对混凝土梁抗拉强度幂值函数预测,对提高建筑物的强度具有重要意义。进行混凝土抗拉强度线性徐变的本构关系分析,综合考虑混凝土的材料非线性效应与时间非线性效应,根据低短期荷载模型设计混凝土结构的非线性徐变多块结构化网格,得到线性荷载下的混凝土梁多块结构化网格模型。试验采用4点弯曲分级加载方式,分别是试件DSHCW-1、试件DSHCW-2、试件DSHCW-3和试件DSHCW-4,进行幂值函数预测。得到不同等级地震作用下的剩余抗拉强度与承载力数值分析,构建混凝土的抗拉强度滞回曲线,实验结果得出,采用该试件模型,能有效提高混凝土梁的抗拉强度,通过对幂值函数准确预测,对混凝土梁结构的强度提高有较大贡献,为高层建筑抗震设计计算或加固提供数学模型和理论基础。  相似文献   

4.
采用基底应力附件固结法计算孔隙率方法与土力学中孔隙率,得到一种高效、高精度的有限元单元分析钢管混凝土柱在扭矩作用下的非线性弹塑性行为方法,实现对强振动下的钢管混凝土结构断裂预测,并分析钢管混凝土柱在往复扭矩荷载作用下的受力行为。对围堰水模型进行冲击模型构建,采用Sierpinski地毯和Menger海绵分形模型设计,采用网格划分方法保证精度的同时显著减少单元数量,提高建筑强度。试验得出,该施工模型能使得基底应力消散时间约为5~7 d,能有效满足基底的排水固结处理时间,从而使得各层土的水平位移基本维持在50 mm以内,地基承载力特征值可达160k Pa,满足设计要求的120 k Pa,提高承压能力。  相似文献   

5.
笔者主要研究钢筋混凝土框架结构在预估罕遇地震作用下的抗倒塌破坏能力,利用SAP2000有限元软件对结构在罕遇地震作用下产生的侧向位移水平和梁、柱端塑性铰水平来阐述结构的破坏程度,分析结构抗地震倒塌破坏能力。研究结果表明:对于大量的一般建筑,在预估的罕遇地震作用下,可能出现薄弱和变形较大的环节,进而结构的抗倒塌能力也不明确。  相似文献   

6.
弹塑性分析方法在高层建筑结构的抗震性能评估分析中有着广泛的应用。针对某框架-剪力墙结构进行小震作用下的弹性计算及大震作用下的弹塑性静力推覆分析,对结构的抗震性能进行评估,并对薄弱区域和构件进行优化和加强。  相似文献   

7.
肖喆 《黑龙江科技信息》2010,(11):10-10,260
介绍静力弹塑性(Pushover)分析的基本原理和方法,并对某高层住宅进行大震作用下静力弹塑性推覆分析,在分析结果的基础上对结构进行一定的调整,以保证结构安全。  相似文献   

8.
超高层建筑结构设计中由于受到剪切变形弹力作用的影响,产生线性梁柱动力弹塑性应变力,影响结构强度。提出一种考虑剪切变形弹性修正的超高层结构设计方法。进行了超高层建筑钢结构剪切变形弹性修正应力拟合模型分析,在各种尺寸下分析梁的荷载位移,由Monter Carlo方法在试件截面进行劈裂破坏面的惩罚约束,得到超高层建筑钢梁结构抗剪连接梁应力-应变全曲线,然后进行了超高层建筑的钢梁结构优化设计。实验结果表明,采用该模型能有效提高超高层钢梁结构的受力强度,实现剪切变形弹性修正,提高超高层建筑的强度和可靠性。  相似文献   

9.
研究地震作用强振动下的钢管混凝土结构断裂点预测方法。钢管混凝土柱在强振动作用下产生纯扭和压扭荷载而导致断裂,分析结构节点延性断裂预测与裂后路径,构建基于次缩减积分的强振动下钢管混凝土结构断裂预测模型,得到一种高效、高精度的有限元单元分析钢管混凝土柱在扭矩作用下的非线性弹塑性行为方法,实现对强振动下的钢管混凝土结构断裂预测,计算钢管混凝土柱在往复扭矩荷载作用下的受力行为。得到钢管混凝土结构断裂模型断裂判据和截面受扭剪应变场,试验得出钢管混凝土矩形截面受扭剪应变场。分析结果可见,采用该预测方法和试验模型,预测得到的钢管混凝土结构试件延性起裂位置与试验结果一致,开裂时刻与试验结果吻合较好,试验结果与理论分析结果吻合较好,精度较高,具有较高的工程适用价值。  相似文献   

10.
目前,纤维石膏速成墙板作为一种新型建筑材料在建筑结构中的应用越来越多了,对其研究也越来越深入。山东建筑大学结构试验室建立足尺模型,并且把速成墙板作为承重墙使用于建筑结构中进行了试验研究。主要研究了速成承重墙板承载力的计算方法,速成承重墙墙板的内力分析,速成承重墙板房屋的抗震性能,但这些都可归结为速成墙体结构的整体静力弹塑性分析,对于结构的动力非线性分析没有进一步进行探讨。基于这个项目中的五层实体模型,通过ANSYS中自带的APDL语言编程建立有限元模型,进一步研究该种墙体结构在输入地震波作用下的非线性地震反应。包括对该建筑结构进行振型分析,采用时程分析法进行非线性地震反应分析以及计算输入三种具有代表性的地震波时结构的反应情况等。  相似文献   

11.
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.  相似文献   

12.
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China's science enterprise by making S&T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party's Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.  相似文献   

13.
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.  相似文献   

14.
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."  相似文献   

15.
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.  相似文献   

16.
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.  相似文献   

17.
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.  相似文献   

18.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.  相似文献   

19.
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment.  相似文献   

20.
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号