拱桥气弹模型的设计、修正与测试

Designing,Updating and Calibrating of a Full Bridge Aeroelastic Model for an Arch Bridge

通过一座主跨为450m的中承式拱桥全桥模型风洞试验总结了大跨径拱桥全桥气弹模型的设计、修正与测试的经验。模型设计是风洞试验的基础,而拱桥模型芯梁设计应考虑到拱桥结构的复杂性和各个振型的特点。首先针对拱桥进行了动力特性分析,即进行气弹模型的有限元建模并对几个结构参数对基频的影响进行了分析。在模型调试过程中,提出了质量影响矩阵法,该方法能明显减少模型调试次数,提高试验效率,是一种可行而高效的调节方法。作为动力特性测试的补充,模型静力刚度检验是进行风洞试验前一个重要环节,最后还介绍了这座中承式拱桥的静力刚度测试的过程。

The experience for designing,updating and calibrating of a full bridge aero-elastic model for an arch bridge is summarized. A half-through arch bridge with the span of 450m is used as a study case.The designing of full bridge model is the basis of the wind tunnel testing,but due to its structural complexity,the designing of full bridge model for an arch bridge becomes more complicated. The dynamic characteristics of the arch bridge are firstly analyzed.A FEM model for the full bridge aero-elastic model is built and the influences of some structural parameters on the dynamic properties are investigated.During the model updating,Mass Influence Ma- trix Method(MIMM)is proposed which can remarkably reduce updating times and proves to be a practical and effective method.As a supplement for calibrating the full bridge aero-elastic model,Static Rigidity Test(SRT)of model is used before wind tunnel test. In the end,the process of SRT is presented for the arch bridge.