基于分布式气动力的大跨度钢箱梁桥多尺度抖振应力响应时域分析及验证

随着大跨度桥梁跨径越来越大、主梁断面宽度的不断增大和复杂化，桥梁的整体抖振响应已经不能满足实际工程的需要，人们还需要获得局部构件的应力响应来进行疲劳、服务性能等深入问题的研究。但目前以抖振的局部应力响应分析为目的的大跨度桥梁有限元建模技术以及相应分析方法还不成熟。本项目拟以理论分析、风洞试验和现场实测为主要手段，研究基于分布式气动力的大跨度钢箱梁桥的多尺度抖振应力响应时域分析方法并验证其有效性，主要包括：1）建立可以同时考虑整体和局部响应的结构多尺度模拟理论框架；2）提出一种针对钢箱梁断面的分布式抖振风压模型，建立复风压气动导纳函数识别技术；3）提出一种钢箱梁断面各点位移、速度函数的分布式自激力模型，开发一套同步多点测压测振的弹簧悬挂刚体节段模型测试装置，建立分布式自激力气动参数的识别技术；4）建立一种同时考虑整体和局部响应的大跨度钢箱梁桥多尺度抖振应力响应时域分析框架。

With the span of bridges being becoming longer and longer, and the girder being becoming wider and more complex, the whole buffeting response of bridges cannot meet the needs of practical engineering. People still want to get the stress responses of local members to investigate the problems of fatigue and service performance. However, the finite element modeling technique and corresponding analytical method are not well developed for the purpose of the local buffeting stress analysis of long span bridges. Taking the theoretical analysis, wind tunnel experiments and field testing as the main means, this project will investigate the multiscale buffeting stress analysis of long-span bridges with steel box girders in the time domain based on distributed aerodynamic forces and verify its effectiveness. The main work includes the following aspects: .1) Build the framework of multiscale simulation of structures considering both the global and local responses..2) Present a distributed wind pressure model for steel box girders and develop a identification technique for the complex aerodynamic admittance functions of wind pressure..3) Present a distributed self-excited force model which is the function of displacement and velocity of points on sections of steel box girders, develop a test device of a spring suspension rigid body section model which can measure the multipoint pressure and vibrations synchronously, and present an identification technique for the aerodynamic parameters of the distributed self-excited force..4) Build the framework of the multiscale buffeting stress analysis of long-span bridges with steel box girders in the time domain considering both the global and local responses.