检索结果-南通市图书馆

Full-scale measurements of dynamic response of suspension bridge subjected to environmental loads using GPS technology

引用

Science china(Technological Sciences) 2010年第2期53卷 469-479页

作者： YI TingHua1,2, LI HongNan1 & GU Ming2 1state key laboratory of Coastal and Offshore engineering, Dalian university of Technology, Dalian 116024, china 2state key laboratory for disaster reduction in civil engineering, tongji university, shanghai 200092, china 1. state key laboratory of Coastal and Offshore engineering Dalian University of Technology Dalian 116024 China2. State Key Laboratory for Disaster Reduction in Civil Engineering Tongji University Shanghai 200092 China

Nowadays, there are many larger and taller engineering structures than in the past. These structures are commonly designed to be more flexible. Thus, they are sensitive to severe wind gust and earthquake tremor. For the dynamic response prediction, finite element (FE) modal updating and structural health monitoring, the dynamic characteristics of a structure are becoming increasingly important. The aim of this paper is to show an emerging tool-the real time kinematic (RTK) global positioning system (GPS), which is used to measure and monitor the low-frequency vibration of Dalian BeiDa Bridge, a medium span suspension bridge. The modal analysis is firstly performed on the developed three-dimensional FE model according to the original blue prints of the bridge to provide the analytical frequencies and mode shapes. The field ambient vibration tests using the accelerometers on the bridge deck are conducted just prior to the use of the GPS system in order to validate the FE model. And then, the calibration test is done to assess the dynamic displacement measurement accuracy of the GPS in three orthogonal directions. The GPS signal properties, such as the amplitude, standard deviations (STD), power spectral density (PSD), and probability density functions (PDF), are studied in details. After that, a structural health monitoring system based on the GPS is devised and installed on the bridge to provide real-time measurement of deck movement. The output-only modal parameter identification is carried out by using the Periodogram method to investigate the responses of the bridge. The result shows that the spectral densities of the displacements measured by the GPS correspond well with the results by the FEM analysis and the accelerometer vibration test. It is concluded that the GPS method is reliable and useful to clarify the ambient vibration response behaviors of the flexible structures. The integration of the GPS and accelerometer methods results in a hybrid arrangement tha

关键词： health monitoring global positioning system real-time kinematic suspension bridge modal analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Wind-resistant studies on tall buildings and structures

引用

Science china(Technological Sciences) 2010年第10期53卷 2630-2646页

作者： GU Ming state key laboratory of disaster reduction in civil engineering, tongji university, shanghai 200092, china 1. state key laboratory of disaster reduction in civil engineering Tongji University Shanghai 200092 China

This paper introduces some aspects of wind-resistant studies of our research team on tall buildings and structures. Wind tunnel tests were carried out on 27 typical tall building models by using wind pressure scanning and HFFB techniques. The characteristics of wind pressures and forces acting on these buildings were analyzed. Some results have been adopted in a shanghai code for structural design of steel tall buildings. Interference effects on wind forces and wind pressures among two and three tall buildings were experimentally investigated with about 10000 testing conditions. Regression analyses of the interference factors under different parameter conditions were made and the main regression formulas are presented. Theoretical study on equivalent static wind loads of tall buildings and structures are then introduced. Especially,a new concept of "mode coupling factor" and a modified SRSS method for wind response and equivalent static wind load of complicated tall buildings and structures with consideration of multi mode contributions and their coupling effects are presented. Finally,practical applications of wind-resistant studies on tall building and structures,taking the Guangzhou New TV Tower as an example,are presented.

关键词： tall building and structure wind pressure and force interference effect equivalent static wind load application

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Homogenization-based multi-scale damage theory

引用

Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 690-698页

作者： LI Jie 1,2 & REN XiaoDan 1 1 School of civil engineering, tongji university, shanghai 200092, china 2 state key laboratory of disaster reduction in civil engineering, shanghai 200092, china 1. School of civil engineering Tongji University Shanghai 200092 China2. State Key Laboratory of Disaster Reduction in Civil Engineering Shanghai 200092 China

The research of modern mechanics reveals that the damage and failure of structures should be considered on different scales. The present paper is dedicated to establishing the multi-scale damage theory for the nonlinear structural analysis. Starting from the asymptotic expansion based homogenization theory, the multi-scale energy integration is proposed to bridge the gap between the micro and macro scales. By recalling the Helmholtz free energy based damage definition, the damage variable is represented by the multi-scale energy integration. Hence the damage evolution could be numerically simulated on the basis of the unit cell analysis rather than the experimental data identification. Finally the framework of the multi-scale damage theory is established by transforming the multi-scale damage evolution into the conventional continuum damage mechanics. The agree- ment between the simulated results and the benchmark results indicates the validity and effectiveness of the proposed theory.

关键词： Multi-scale damage representation asymptotic method constitutive model numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Experimental investigation of damage behavior of RC frame members including non-seismically designed columns

引用

Earthquake engineering and engineering Vibration 2009年第2期8卷 301-311页

作者： Chen Linzhi,Lu Xilin,Jiang Huanjun and Zheng Jianbo state key laboratory of disaster reduction in civil engineering,tongji university,shanghai 200092,china PhD Candidate Professor Associate Professor Master of engineering state key laboratory of disaster reduction in civil engineering Tongji University Shanghai 200092 China state key laboratory of disaster reduction in civil engineering Tongji University 1239 Siping Road Shanghai 200092 China

Reinforced concrete （RC） frame structures are one of the mostly common used structural systems, and their seismic performance is largely determined by the performance of columns and beams. This paper describes horizontal cyclic loading tests often column and three beam specimens, some of which were designed according to the current seismic design code and others were designed according to the early non-seismic Chinese design code, aiming at reporting the behavior of the damaged or collapsed RC frame strctures observed during the Wenchuan earthquake. The effects of axial load ratio, shear span ratio, and transverse and longitudinal reinforcement ratio on hysteresis behavior, ductility and damage progress were incorporated in the experimental study. Test results indicate that the non-seismically designed columns show premature shear failure, and yield larger maximum residual crack widths and more concrete spalling than the seismically designed columns. In addition, longitudinal steel reinforcement rebars were severely buckled. The axial load ratio and shear span ratio proved to be the most important factors affecting the ductility, crack opening width and closing ability, while the longitudinal reinforcement ratio had only a minor effect on column ductility, but exhibited more influence on beam ductility. Finally, the transverse reinforcement ratio did not influence the maximum residual crack width and closing ability of the seismically designed columns.

关键词： reinforced concrete frame member cyclic test hysteresis behavior damage behavior seismic performance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recent research and applications of GPS based technology for bridge health monitoring

引用

Science china(Technological Sciences) 2010年第10期53卷 2597-2610页

作者： YI TingHua1,2, LI HongNan1 & GU Ming2 1 Faculty of Infrastructure engineering, Dalian university of Technology, Dalian 116023, china 2 state key laboratory for disaster reduction in civil engineering, tongji university, shanghai 200092, china 1. Faculty of Infrastructure engineering Dalian University of Technology Dalian 116023 China2. State Key Laboratory for Disaster Reduction in Civil Engineering Tongji University Shanghai 200092 China

Today,long-span bridges are being designed to be more flexible and to resist extensive impacts from changes in temperature,severe wind gusts and earthquake tremors. Structural responses (especially displacement) of bridge structures are becoming increasingly important for the finite element (FE) modal updating,structural response prediction and safety evaluation. Methods of global displacement sensing were developed for these needs. This paper presents an overview of current research and development activities in the field of bridge health monitoring using the global positioning system (GPS). The GPS monitoring technology and its accuracy assessment method are also briefly described. Finally,existing problems and promising research efforts in the GPS based bridge health monitoring are discussed.

关键词： global positioning system (GPS) structural health monitoring (SHM) bridge measurement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

REYNOLDS NUMBER EFFECTS IN TALL BUILDING WIND TUNNEL TESTS

引用

Journal of Hydrodynamics 1996年第4期8卷 56-62页

作者： Cheng Zhao Shi Zong-cheng Zhang Feng(state key Lab. for disaster reduction in civil Eng., tongji Univ shanghai 200092, P.R. china) tongji Univ Shanghai China

In wind tunnel tests of tall building models comprised of rounded or streamlined surfaces, Reynolds Number Effects (RNE) may be remarkable. In most researches and projects, owing to the presence of sharp edged corners at model, RNE was often treated as negligible, and data colleCted in subcritical flow regime were applied directly to designs which were sure to be supercritical without any modification. But it was proved necessary to take RNE into consideration when a model had predominant rounded smooth surface(s). Some research activities were devoted to the mentioned condition and two experimental techniques accompanied by two wind tunnel model tests were introduced in the article. The authors also presented some amusing phenomenon such as extremely low pressure coefficients caused by the separating bubbles when now past sharp edged corners, unsymmetrical pressure coefficient distributions commenced by biased gap f'low (seen Figs. 3, 4) while models were placed symmetrically in the approaching flow.

关键词： Reynolds Number Effect wind tunnel simulation nows around building

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

高层建筑顺风向动力干扰效应的试验研究

引用

同济大学学报（自然科学版） 2002年第12期30卷 1417-1422页

作者：黄鹏顾明同济大学土木工程防灾国家重点实验室上海200092

采用高频动态天平技术和气动弹性模型技术对两个形状相同的方形截面高层建筑的顺风向动力干扰效应进行了风洞实验研究 .两种实验方法所得的结果具有良好的一致性 .最后应用人工神经网络方法对试验结果进行了模拟和推广 ,给出了顺风向动... 详细信息

采用高频动态天平技术和气动弹性模型技术对两个形状相同的方形截面高层建筑的顺风向动力干扰效应进行了风洞实验研究 .两种实验方法所得的结果具有良好的一致性 .最后应用人工神经网络方法对试验结果进行了模拟和推广 ,给出了顺风向动力干扰因子的等值线图。

关键词：高层建筑干扰效应顺风向动力风荷载高频动态测力天平气动弹性模型

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

大跨度屋盖表面风压系数的试验研究

引用

同济大学学报（自然科学版） 2002年第12期30卷 1423-1428页

作者：周晅毅顾明同济大学土木工程防灾国家重点实验室上海200092

以两个大跨度屋盖结构为例 ,通过风洞模拟试验说明大跨度屋盖表面风压的复杂性 .

关键词：试验研究大跨度屋盖结构平均风压脉动风压

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

群体高层建筑风荷载干扰的研究现状及展望

引用

同济大学学报（自然科学版） 2003年第7期31卷 762-766页

作者：顾明黄鹏同济大学土木工程防灾国家重点实验室上海200092

群体高层建筑的风荷载和响应的干扰效应是建筑结构抗风研究和应用中十分关注的问题 .为此 ,总结了大量国内外文献的研究工作 ,包括作者进行的上海金茂大厦风洞实验的部分研究成果 ,系统介绍了群体建筑风荷载干扰的研究历史、研究状况、... 详细信息

群体高层建筑的风荷载和响应的干扰效应是建筑结构抗风研究和应用中十分关注的问题 .为此 ,总结了大量国内外文献的研究工作 ,包括作者进行的上海金茂大厦风洞实验的部分研究成果 ,系统介绍了群体建筑风荷载干扰的研究历史、研究状况、取得的主要成果和规范应用情况 ,以及当前的研究方向。

关键词：高层建筑风荷载响应干扰效应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

单通道测压管路系统的优化设计

引用

同济大学学报（自然科学版） 2003年第7期31卷 798-802页

作者：周晅毅顾明同济大学土木工程防灾国家重点实验室上海200092

建筑物的脉动风压的信息对于结构风振响应的计算有重要意义 .为了避免测压管路系统测量的脉动风压力发生畸变 ,需采用一些气动措施 ,如加限制器的方法是方便而有效的 .为此提出了对串联限制器的测压管路进行优化设计的一种方法 ,并对优... 详细信息

建筑物的脉动风压的信息对于结构风振响应的计算有重要意义 .为了避免测压管路系统测量的脉动风压力发生畸变 ,需采用一些气动措施 ,如加限制器的方法是方便而有效的 .为此提出了对串联限制器的测压管路进行优化设计的一种方法 ,并对优化后测压管路系统的频率响应函数进行了实验测试 ,理论计算的频率响应函数与实验测量值吻合得很好 .进一步对比了当输入信号为随机压力时 ,测压管路系统分别为优化后的测压管路系统、强阻尼及弱阻尼测压系统测量的压力信号 .

关键词：测压管路系统优化限制器

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：