考虑人体动力性能的人群-空间大跨板相互作用研究

Modern designers have adored the conception philosophy of large scale and long-span architecture along with the rapid development of national economy and infrastructure construction. A lot of structures under crowd excitation have behaved on remarkable flexibility and low damping energy dissipation characteristics, such as footbridges, theater stage and sports venues. The vibrational performances of these spatial long-span plates induced by dynamic crowd activity including the dynamic characteristics of body have become the key basic scientific problems for researchers. Firstly, the bipedal modal is used to emulate pedestrian, which includes the dynamic characteristics contribution of human body and foot gait activities. A dynamic bipedal crowd–spatial long-span plate structure system is established considering the contribution from body mass, stiffness and damping to structural performances. Secondly, a dynamic interaction model between crowd and spatial long-span plate is further built and it considers the interactions among pedestrians based on the Cellular Automate model. Thirdly, the vibrational test of the spatial long-span plate is operated to verify the reliability of the theory of bipedal crowd- spatial long-span plate interaction model. Finally, the vibrational evaluation system of the spatial long-span plate induced by crowd excitation is studied based on the above theoretical and experimental results. The main purpose of the research is used to explore the structural dynamic response and performances of the spatial long-span plate under crowd excitation. The study results will provide important scientific basis and theoretical guidance for the long-span structural design, performance evaluation and vibrational control of the long-span plate under crowd excitations.

随着国民经济和城市基础设施建设的快速发展，现代结构追求大尺度、大空间的设计理念，大量结构表现出显著的轻柔和低阻尼耗能特性，如人行桥、舞台剧场以及体育场馆等。如何考虑人群动力性能对空间大跨结构的人致振动机理已成为有待解决的关键性基础科学问题。研究首先用含有人体动力特性以及步态细节的双足人体模型建立人群-空间大跨板结构动力系统理论，该系统中考虑了人体质量、刚度以及阻尼等动力特性对结构性能的贡献。其次基于元胞自动机模型考虑人与人的相互作用并进一步建立人群-空间大跨板相互作用模型。再利用现浇大跨板结构进行试验，以验证双足人群-空间大跨板系统理论的可靠性。最后基于理论和试验研究结果，对空间大跨板结构的人致振动评价体系进行研究。研究主要探索活动人群对空间大跨板的动力响应以及动力性能的影响机理，将为空间大跨板的设计、使用性能评估以及振动控制提供重要的科学依据和理论指导。

随着现代结构大尺度、大空间的设计理念普及，大量结构表现出显著的轻柔和低阻尼低耗能特性，结构的人致振动舒适性问题亟需解决。本项目用含有人体动力特性以及步态细节的双足人体模型建立行人-空间大跨板结构动力系统理论，该系统中考虑了人体质量、刚度以及阻尼等动力特性对结构性能的贡献，并通过室内实验和野外实验验证了部分结论的有效性。研究表明人体参数变化对结构动力学性能有重要的影响，人腿刚度的增加会促使结构响应幅值增加，而对结构频率和阻尼影响不显著；人体阻尼的增加有助于增强结构阻尼耗能性能和降低结构响应幅值；人的步频在关键频率处会激起结构的剧烈响应，而步频的变化对结构阻尼和频率的影响微乎其微。再对人群特征研究表明，人群在结构上的分布对结构动力特性有着显著影响，人群均匀分布时最能显著降低结构的频率和增加结构阻尼性能；人群与结构质量比越大，当人群处于某个关键分布时，显著增强了结构整体的柔性，而阻尼也进一步增强。本研究结论对大尺度结构的人致振动舒适性控制设计有着重要的指导意义。通过本研究说明：要有效降低结构的人致振动风险可以通过设计人群分布密度、人群活动频率和人群分布形式得以实现。