EAPSI:Investigating Dynamic Loads and Response of Bridges and Moving Vehicles Subjected to Extreme Wind Gusts

柔性结构，如大跨度悬索桥，在超过特定风速的情况下，可能会受到大振幅振动和灾难性破坏的影响。该项目将研究用于在风洞中分析结构的实验方法，以避免像1940年塔科马窄桥坍塌那样的灾难，并改进车辆设计，以避免因突然的侧风而倾覆，如龙卷风或微爆炸。这项研究将在日本京都大学的桥梁工程实验室与白藤博一博士合作进行。日本继续挑战桥梁工程的极限，神户的赤桥-海乔大桥或大阪的纳米屋大桥，可能会经历几次极端的风事件、台风、龙卷风和微爆发，从而提高了这些研究的适用性。用传统的频域方法不可能得到结构在阵风(时变)作用下的气动弹性载荷和响应。最近发展了分别使用有理函数近似和抖振指标函数的自激、运动诱导和抖振、湍流诱导载荷的时域方法。这些方法也更适用于有限元分析和疲劳寿命估算。该项目将研究有理函数和抖振指示函数技术的应用，因为它涉及到桥梁主梁截面和移动车辆在突然横风作用下的应用。该项目的结果将为提高桥梁和车辆设计的安全性提供见解，以应对龙卷风和微爆炸等阵风。该NSF EAPSI奖是与日本科学促进会合作资助的。

Flexible structures, such as long-span suspension bridges, can be susceptible to large amplitude vibrations and catastrophic failure above a specific wind speed. This project will investigate the experimental methods used to analyze structures in a wind tunnel in order to avoid disasters like the Tacoma Narrows Bridge collapse in 1940 and improve the design of vehicles to avoid overturning due to sudden crosswinds, like those from tornadoes or microbursts. This research will be conducted at the Bridge Engineering Laboratory at Kyoto University in Japan in collaboration with Dr. Hiromichi Shirato. Japan continues to push the limits of bridge engineering, the Akashi-Kaikyo Bridge in Kobe or the Namihaya Bridge in Osaka, and can experience several extreme wind events, typhoons, tornadoes and microbursts enhancing the applicability of these studies. The aeroelastic loads and response of structures due to gusty (time dependent) winds is not possible using the traditional frequency domain methods. Time-domain methods for both self-excited, motion-induced, and buffeting, turbulence-induced, loads have been recently developed using rational function approximations and buffeting indicial functions, respectively. These methods are also more applicable for finite element analysis and fatigue life estimations. The project will investigate the applications of rational function and buffeting indicial function technology as it relates to a bridge girder section and a moving vehicle subjected to a sudden crosswind. The results from the project will provide insights to improve the safety of the design of bridges and vehicles for gusty winds like tornadoes and microbursts. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.