SYNCHRONISATION IN DYNAMIC LOADING DUE TO MULTIPLE PEDESTRIANS AND OCCUPANTS OF VIBRATION-SENSITIVE STRUCTURES

多个行人和振动敏感结构中的人员造成的动态载荷同步

• 批准号: EP/I029567/1
• 负责人: James Brownjohn
• 金额: $ 66.09万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FI029567%2F1
• 关键词: SYNCHRONISATION; DYNAMIC; LOADING; DUE; MULTIPLE

For vibration-sensitive structures such as footbridges, floors and stadia, dynamic loads due to humans walking, running, jumping or bouncing are poorly understood and present a major challenge for design. Footbridges and stadia are often highly visible landmark structures with conflicting requirements for lightweight elegance with low vibration levels for occupant/user comfort. Design mistakes attract significant publicity (Millennium Bridge) and successes attract accolades (2012 Olympic Velodrome). Meeting the challenge requires scientifically rational design guidance which is not overly conservative as a result of uncertainties in the loading. Hence in a country that leads the world for design of such structures we also need to lead in development of state of the art design guidance for vibration serviceability. Despite significant recent developments, there remain major deficiencies in guidance for dynamic loads due to groups and crowds of people owing to simplistic assumptions of coordination by users and occupants. We simply have very limited understanding about how synchronisation works among pedestrians, joggers and football fans (for example) so we make very simple assumptions about perfect synchronisation and totally coordinated activities that lead to worst case conservative design.This research project is a collaboration between psychologists researching balance control, sensory motor function and timing of movement, and structural engineers researching human dynamic loading on and performance of 'assembly structures' and who have common interests in synchronisation. For the psychologists, the interests concern performance of musicians, dancers and sportsmen (e.g. rowers) ,while for the engineers the concern is the nature of the effective maximum dynamic loading on a structure due to moving human occupants. Studies on synchronisation have to date been limited to two individuals; the methods will be extended and developed for groups of increasing size in a range of circumstances to assess the relative importance of different cues. Such cues would be visual perception of motion of neighbours, sound of footfalls or music and physical contact and motion both of neighbours and of the support (such as a wobbly footbridge or bouncy grandstand cantilever).Measurement of human motion that leads to derivation of synchronisation measures and aggregate dynamic loading is by itself a complex process since direct measurement, even of forces from a single pedestrian in a controlled laboratory environment, requires an expensive instrumented treadmill. Measurement of more than two people beyond the laboratory is a major research challenge that we intend to manage using wireless inertial sensors and CCTV-based motion capture, technology to be evaluated for individuals in the laboratory-limited environment. These are not simple technologies but direct experience, observation and discussions tell us they are the way forward to measuring human motion in large-scale environments.Being driven by engineers, the major outcome of the research will be a means to estimate the maximum dynamic loading and determine the governing loading scenario, leading to more rational guidance and competitive designs. The last part of the experimental research involves well controlled full scale tests on exemplar structures.Understanding of the mechanisms and factors on synchronisation will be a bi-product benefitting the wider communities where human coordination of periodic activities is important.

对于振动敏感的结构，如人行桥，地板和体育场，由于人类行走，跑步，跳跃或弹跳的动态载荷知之甚少，并提出了一个重大的设计挑战。人行天桥和体育场通常是高度可见的地标性建筑，它们对轻质优雅和低振动水平的要求相互冲突，以保证居住者/用户的舒适性。设计上的失误吸引了大量的公众关注（千禧桥），而设计上的成功吸引了赞誉（2012年奥运会自行车馆）。应对这一挑战需要科学合理的设计指导，而不是由于载荷的不确定性而过于保守。因此，在一个在此类结构设计方面处于世界领先地位的国家，我们还需要引领振动适用性最新设计指南的发展。尽管最近取得了重大进展，但由于用户和居住者协调的简单假设，对人群和人群引起的动态载荷的指导仍然存在重大缺陷。我们对行人、慢跑者和足球迷之间的同步是如何运作的了解非常有限（例如）所以我们对完美的同步和完全协调的活动做出非常简单的假设，导致最坏情况下的保守设计。这个研究项目是研究平衡控制，感觉运动功能和运动时机的心理学家之间的合作，以及研究“装配结构”上的人体动态载荷和性能的结构工程师，他们对同步有共同的兴趣。对于心理学家来说，关注的是音乐家、舞蹈家和运动员（如赛艇运动员）的表现，而对于工程师来说，关注的是由于移动的人类居住者而引起的结构上的有效最大动态载荷的性质。同步的研究迄今为止仅限于两个人，该方法将被扩展和开发的规模不断增加的群体在一系列的情况下，以评估不同的线索的相对重要性。这些线索将是对邻居运动的视觉感知，脚步声或音乐声以及邻居和支持者的身体接触和运动（例如摇摆的人行桥或有弹性的看台悬臂）。导致同步测量和总动态载荷的导出的人体运动的测量本身是复杂的过程，因为直接测量，即使是在受控的实验室环境中来自单个行人的力，也需要昂贵的仪器化跑步机。在实验室之外测量两个以上的人是一个重大的研究挑战，我们打算使用无线惯性传感器和基于CCTV的运动捕捉来管理，这些技术将在实验室有限的环境中对个人进行评估。这些都不是简单的技术，但直接的经验、观察和讨论告诉我们，它们是在大规模环境中测量人体运动的前进方向。在工程师的推动下，研究的主要成果将是估算最大动态载荷和确定控制载荷方案的方法，从而提供更合理的指导和更具竞争力的设计。实验研究的最后一部分涉及对范例结构进行控制良好的全尺寸测试。对同步机制和因素的理解将是一个双产品，有利于更广泛的社区，其中人类协调周期性活动是重要的。

项目成果

Learn++ for Robust Object Tracking

• DOI: 10.5244/c.28.28
• 发表时间: 2014-09
• 作者: Feng Zheng;Ling Shao;J. Brownjohn;V. Racic

Measuring human-induced vibrations of civil engineering structures via vision-based motion tracking

• DOI: 10.1016/j.measurement.2016.01.015
• 发表时间: 2016-04
• 期刊: Measurement
• 影响因子: 5.6
• 作者: Feng Zheng;Ling Shao;V. Racic;J. Brownjohn

Interaction between Walking Humans and Structures in Vertical Direction: A Literature Review

• DOI: 10.1155/2016/3430285
• 发表时间: 2016-06
• 期刊: Shock and Vibration
• 影响因子: 1.6
• 作者: E. Shahabpoor;A. Pavic;V. Racic

Modelling framework for dynamic interaction between multiple pedestrians and vertical vibrations of footbridges

• DOI: 10.1016/j.jsv.2016.05.047
• 发表时间: 2016-09
• 期刊: Journal of Sound and Vibration
• 影响因子: 4.7
• 作者: F. Venuti;V. Racic;Alessandro Corbetta

Acceleration response spectrum for prediction of structural vibration due to individual bouncing

用于预测个体弹跳引起的结构振动的加速度响应谱

• DOI: 10.1016/j.ymssp.2016.02.032
• 发表时间: 2016-08
• 期刊: Mechanical Systems and Signal Processing
• 影响因子: 8.4
• 作者: Chen Jun;Wang Lei;Racic Vitomir;Lou Jiayue
• 通讯作者: Lou Jiayue