朱乐东
长期从事土木工程结构的抗风研究工作
个性化签名
- 姓名:朱乐东
- 目前身份:
- 担任导师情况:
- 学位:
-
学术头衔:
“973”、“863”首席科学家, 博士生导师, 教育部“新世纪优秀人才支持计划”入选者
- 职称:-
-
学科领域:
土木建筑工程
- 研究兴趣:长期从事土木工程结构的抗风研究工作
朱乐东,1965年生,浙江宁波人,同济大学土木工程防灾国家重点实验室、桥梁工程系研究员,博士生导师。1986年毕业于同济大学结构工程系土建结构工程专业,获工学学士学位。1989年毕业于同济大学结构工程学院结构工程专业,获工学硕士学位。2002年毕业于香港理工大学土木及结构工程系,获哲学博士学位。
1989年起在同济大学桥梁工程系和同济大学土木工程防灾国家重点实验室工作,历任助教、助理研究员、副研究员和研究员。曾于1995年在德国HOCHTIEF公司从事合作研究工作;1997年香港科技大学访问学者。现任同济大学桥梁工程系桥梁抗风研究室主任、土木工程防灾国家重点实验室风洞试验室副主任、桥梁抗风技术交通行业重点实验室副主任,中国空气动力学学会风工程和工业空气动力学专业委员会委员、副秘书长,国际桥梁与结构工程协会会员,上海公路学会会员。被评为2004年度上海市曙光学者,2005年入选教育部新世纪优秀人才计划。
长期从事土木工程结构的抗风研究工作,先后参加多项国家自然科学基金项目(包括重大、重点和面上项目)和国家863项目及大量省部级科研项目。参加了几十座大跨度桥梁和建筑结构的抗风性能研究工作,其中主持了“徐浦大桥”、“重庆长江二桥”、“广东湛江海湾大桥”、“南京长江三桥”、“越南洛苗斜拉桥”、“宁波象山港大桥”、“上海虹口体育中心体育场”、“青岛机场候机楼”、“杭州市民中心”、“广州新电视塔”等二十多个重大工程结构的抗风研究项目。创造性地建立了用于考虑主梁约束扭转刚度影响的缆索承重桥梁动力性能分析的“三梁式模型”;在国际上率先建立了基于气动斜片条概念的斜风作用下大跨度桥梁构件六分量抖振力模型和随机抖振响应实用频域分析方法、并开发了配套的斜风作用下主梁斜截面颤振导数以及气动六分力系数测量的风洞试验技术;提出了考虑全桥振动效应和固有振型空间特性的桥梁颤振性能风洞试验节断模型质量系统模拟方法;提出了考虑全桥振动效应和固有振型空间特性的桥梁涡激共振性能风洞试验节断模型质量系统模拟方法以及模型与实桥涡激共振响应幅值换算公式。在国内外学术杂志和学术会议上发表学术论文70多篇,其中被SCI收录11篇、EI收录17篇和ISTP收录7篇。曾获国家自然科学四等奖、国家教委科技进步一等奖和上海市科技进步一等奖各一次,参编的《现代桥梁抗风理论与实践》获2006年“首届中华优秀出版物(图书)奖”并入选“三个一百”原创科技图书。
-
主页访问
4731
-
关注数
0
-
成果阅读
801
-
成果数
14
【期刊论文】Buffeting response of long-span cable-supported bridges under skew winds. Part 1: theory
朱乐东, L. D. Zhu, Y. L. Xu
Journal of Sound and Vibration 281(2005)647-673,-0001,():
-1年11月30日
A finite-element-based framework for buffeting analysis of long-span cable-supported bridges under skew winds is developed in the frequency domain utilizing the linear quasi-steady theory and the strip theory of aerodynamics in conjunction with the pseudo excitation method. A set of universal expressions for six components of buffeting forces is first derived in association with oblique cross-sections of bridge components, in which the buffeting forces are formed with respect to the wind coordinate system and then converted to those with respect to the structural coordinate system. Skew mean wind and three orthogonal components of velocity fluctuations can thus be easily handled without any further decomposition. The coherence between velocity fluctuations of wind turbulence at any two arbitrary spatial points is considered in the global wind coordinate system rather than in the global structural coordinate system. Aeroelastic stiffness and damping matrices due to self-excited forces are then taken into consideration in terms of the 18 flutter derivatives with respect to the oblique cross-sections. The pseudo-excitation method is finally employed to solve efficiently the fully coupled 3D buffeting problem of long-span cable-supported bridges under skew winds with the effects of multi-modes and spatial modes, inter-mode coupling and aerodynamic coupling, and the interaction among major bridge components being naturally included.
-
102浏览
-
0点赞
-
0收藏
-
0分享
-
325下载
-
0评论
-
引用
【期刊论文】Tsing Ma bridge deck under skew winds—Part II: flutter derivatives
朱乐东, L. D. Zhu, , Y. L. Xu, H. F. Xiang
Journal of Wind Engineering and Industrial Aerodynamics 90(2002)807-837,-0001,():
-1年11月30日
s paper addresses the measurement of eight flutter derivatives of a typical oblique strip of the Tsing Ma bridge deck under skew winds. The wind tunnel test technique developed for this measurement includes the design of oblique sectional model, the development of a dynamic test rig, and the application of unifying least-square (ULS) method for identification. The eight identified flutter derivatives of discrete values are first fitted to obtain eight flutter derivative curves as functions of both wind inclination and yaw angle. Based on these curves, the effects of wind inclination and yaw angle on aeroelastic damping and stiffness, in particular on critical wind speed, are then discussed. Furthermore, the measured flutter derivatives of the bridge deck under skew winds are compared with those obtained from the empirical formulae derived from the skew wind theory. Finally, the critical wind speeds from the measured flutter derivative A2• curves are also compared with those from the A2•curves estimated by the empirical formulae. © 2002 Elsevier Science Ltd. All rights reserved.
Tsing Ma suspension bridge, Oblique strip, Skew wind, Flutter derivatives, Unifying least-square method, Skew wind theory
-
63浏览
-
0点赞
-
0收藏
-
0分享
-
229下载
-
0评论
-
引用
【期刊论文】Buffeting response of long-span cable-supported bridges under skew winds. Part 2: case study
朱乐东, Y. L. Xu, L. D. Zhu
Journal of Sound and Vibration 281(2005)675-697,-0001,():
-1年11月30日
The finite-element-based framework for buffeting analysis of long-span cable-supported bridges under skew winds has been presented in Part 1 of this paper. The framework is now applied to the Tsing Ma Suspension Bridge in Hong Kong as a case study. The wind velocities and bridge responses measured by the Wind and Structural Health Monitoring System (WASHMS) of the bridge during Typhoon Sam in 1999 are first analyzed to find the skew wind characteristics surrounding the bridge, the modal damping ratios and acceleration responses of the bridge. The buffeting responses of the bridge under skew winds during Typhoon Sam are then computed using the wind characteristics and modal damping ratios measured from the field and the aerodynamic coefficients and flutter derivatives of the bridge deck and tower measured from the wind tunnel under skew winds. The computed acceleration responses of the bridge deck and cable are finally compared with the responses measured from the field. The comparison is found to be satisfactory in general and the case study forms a good practical demonstration for the verification of the proposed method for buffeting analysis of long-span cable-supported bridges under skew winds.
-
56浏览
-
0点赞
-
0收藏
-
0分享
-
317下载
-
0评论
-
引用
【期刊论文】Triple-girder model for modal analysis of cable-stayed bridges with warping effect
朱乐东, L. D. Zhu, H. F. Xiang, Y. L. Xu
Engineering Structures 22(2000)1313-1323,-0001,():
-1年11月30日
In the modal analysis of cable-stayed bridges using the finite element approach, the single-girder model or the double-girder model is often adopted for modeling the bridge deck. These two models are simple and easy to embody in commercial software packages, but the warping stiffness (constant) of bridge deck cannot be properly taken into consideration. This paper thus presents a triple-girder model consisting of one central girder and two side girders symmetrically connected to each other by transverse links. The proposed triple-girder model can easily consider the warping stiffness and other section properties of the bridge deck, and at the same time keep the user-friendly features in the single-girder model. The Nanpu cable-stayed bridge, built recently in China, is then taken as a case study to verify the rationality of the proposed triple-girder model through a comparison with measured data. The study shows that the modal properties of the cable-stayed bridge obtained from the modal analysis using the triple-girder model are more reasonable and close to the measured data. Further studies of four more cable-stayed bridges in China highlight that the extent of the warping effect depends greatly on the type of bridge deck and on the type of bridge tower–cable system. A simple approach for estimating some section properties of typical open-section decks is also suggested to further facilitate the use of the triple-girder model. © 2000 Elsevier Science Ltd. All rights reserved.
Cable-stayed bridge, Modal analysis, Triple-girder model, Warping constant, Case study
-
89浏览
-
0点赞
-
0收藏
-
0分享
-
200下载
-
0评论
-
引用
【期刊论文】Tsing Ma bridge deck under skew winds-Part I: Aerodynamic coefficients
朱乐东, L.D. Zhu, , Y.L. Xu, F. Zhang, H.F. Xiang
Journal of Wind Engineering and Industrial Aerodynamics 90(2002)781-805,-0001,():
-1年11月30日
This paper aims to measure six static aerodynamic coefficients, while a companion paper addresses the measurement of eight flutter derivatives, of a typical oblique strip of the Tsing Ma suspension bridge deck under skew winds. The wind tunnel test technique developed for the aerodynamic coefficient measurement includes the design of oblique sectional models, the development of a test rig and a measurement system, and the analysis of test results. The effects of model end angle on the aerodynamic coefficients are investigated and found to be very small on lift, drag and pitching moment coefficients. The measured results are then fitted to obtain the six aerodynamic coefficient curves as functions of both wind inclination and yaw angle, which will be used in a later comparison of buffeting response of the bridge between field measurement and analysis. The measurement results reveal that the drag, lift and pitching moment coefficients are much larger than the crosswind force, rolling moment and yawing moment coefficients. The variation of lift coefficient with wind yaw angle is small, but the value of drag coefficient decreases with increasing wind yaw angle and the value of pitching moment coefficient increases with increasing wind yaw angle. The obtained six aerodynamic coefficient curves are also used to examine the currently used cosine rule for buffeting analysis of a bridge under yaw winds. It is found that the traditional cosine rule is generally inadequate, particularly in the cases of large wind yaw angle.
Tsing Ma suspension bridge, Oblique strip, Skew winds, Aerodynamic coefficients, Wind tunnel test, Cosine rule
-
54浏览
-
0点赞
-
0收藏
-
0分享
-
269下载
-
0评论
-
引用
朱乐东, 李超, 郭震山
结构工程师第21卷第6期2005年12月/Structural Engineers Vol. 21, No. 6 Dec. 2005,-0001,():
-1年11月30日
提出了用一个人工低风速的紊流场作为主要环境随机振动源的环境随机振动试验方法,并用该试验方法和随机振动信号频域分析方法对南京长江三桥全桥气弹模型进行了模态识别。经与有限元计算结果比较后可知,所识别的全桥气弹模型固有频率和振型结果令人满意。
全桥气弹模型, 环境随机振动, 频域法, 模态识别
-
49浏览
-
0点赞
-
0收藏
-
0分享
-
66下载
-
0评论
-
引用
朱乐东
同济大学学报第27卷第2期1999年4月/JOURNAL OF TONGJI UNIVERSITY Vol. 27 No. 2 Apr. 1999,-0001,():
-1年11月30日
介绍了所编制的实桥环境随机振动测试数据处理及固有模态识别程序EDPFDM。该程序以频域法为基础,可对经实桥分组环境随机振动测试而得的大量数据进行快速自谱、互谱及相位差和凝聚性分析,从而识别出桥梁的固有模态及对应的结构阻尼比的估计范围。以香港汲水门大桥固有模态环境随机振动测试为实例,结合用MSC- NASTRAN通用程序的模态分析结果,证明了程序EDPFDM的效率和可靠性。
环境随机振动, 频域法, 固有模态, 分段平滑
-
58浏览
-
0点赞
-
0收藏
-
0分享
-
106下载
-
0评论
-
引用
朱乐东, 张之勇, 张志成, 朱宏平
振动工程学报第12卷第4期1999年12月/Journal of Vibration Engineering Vol. 12 No. 4 Dec 1999,-0001,():
-1年11月30日
汲水门大桥是一座主跨430米、双塔平行双索面、公铁两用双层斜拉桥,横跨香港马湾岛和大屿山岛之间的汲水门水道。在通车之前对该桥进行了实桥环境随机振动试验研究,以获得对桥梁抗震、抗风、健康监测、故障诊断等非常重要的结构固有模态(包括固有频率、振型及对应的阻尼比)。对主梁上的11个测站(33个测点)和两桥塔上的4个测站(16个测点)分4组进行了环境随机振动信息的记录,并利用自编的模态识别程序EDPFDM对所记录的信号进行了处理。在0~6Hz范围内共识别出主梁竖向弯曲振动为主的模态10阶,主梁横向弯曲振动为主的模态4阶,主梁扭转振动为主的模态6阶。经比较,固有频率和振型的试验结果与MSC-NAS-TRAN程序的分析结果十分接近。
随机振动, 频谱分析, 固有模态, 模态识别
-
73浏览
-
0点赞
-
0收藏
-
0分享
-
67下载
-
0评论
-
引用
【期刊论文】桥梁涡激共振试验节段模型质量系统模拟与振幅修正方法
朱乐东
工程力学第22卷第5期2005年10月/ENGINEERING MECHANICS Vol. 22 No. 5 Oct. 2005,-0001,():
-1年11月30日
节段模型风洞试验是研究涡激共振风速锁定范围和最大振动幅值的一种重要手段。基于一个具有自激特性的经验线性涡激力模型,从涡激共振微分方程出发,推导了涡激共振试验节段模型质量系统模拟公式,并建立了相应的模型与实桥之间涡激共振幅值的换算关系,给出了涡激共振幅值的振型修正系数和阻尼修正系数公式。由此,通过合理的质量系统模拟和响应幅值换算,可在二维的涡激共振节段模型试验中考虑实桥的结构和振动的三维特性的影响。
桥梁与隧道工程, 涡激共振, 涡激力模型, 节段模型风洞试验, 等效质量, 振型修正系数, 阻尼修正系数
-
47浏览
-
0点赞
-
0收藏
-
0分享
-
76下载
-
0评论
-
引用
朱乐东, 常光照
桥梁建设2006年第2期,-0001,():
-1年11月30日
扁平箱形截面桥梁的颤振临界风速与风偏角的关系明显地受到风攻角的影响。在0°风攻角情况下,扁平箱形截面流线性好,其颤振性能与平板接近,颤振临界风速随风偏角的增加而增加,用传统的平均风分解方法可以获得较好的结果;而对于非0°风攻角的情况,扁平箱形截面的流线性变差,随着风偏角的增加其颤振临界风速呈起伏变化,最低值一般在斜风的情况下出现,此时,传统的平均风分解方法不再适用。
扁平箱形截面, 斜风, 风偏角, 风攻角, 颤振临界风速, 风洞试验
-
42浏览
-
0点赞
-
0收藏
-
0分享
-
76下载
-
0评论
-
引用