桥梁断面颤振导数识别的耦合自由振动测力法

随着桥梁跨度的不断增加,桥面风致振动所引起的气动力非定常效应和非线性效应较为显著,钝体断面的自激力高次谐波分量不可忽略.为研究非线性自激力特性,课题组开发了一套高精度测力天平.利用此天平首先采用Scanlan线性自激力模型测得桥梁断面颤振导数,并与修正最小二乘法识别结果进行对比,再用Newmark-β法反算位移,取得了很好的结果,验证了天平的可靠性.本方法因适用于非线性自激力研究,为下一步工作建立非线性自激力模型提供了很好的手段.

Coupled Free Vibration Force Measurement Technique for Identifying Flutter Derivatives of Bridge Decks

With the increasing of the bridge span , aerodynamic unsteady and nonlinear effect caused by wind-induced vibration of bridge decks is more obvious , and the high harmonics of self -excited force in the bluff section should not be ignored .In order to study the nonlinear characteristics of self -excited force , our research group developed a high precision force balance .With the balance bridge section flutter derivatives were measured using Scanlan＇s linear self-excited force model , then the results were compared with those identified by MLS method .Furthermore , the New mark-βmethod was used to calculate displacement reversely , which achieved good results and verified the reliability of the balance .Applicable to study nonlinear self -excited force , the method provides a good means for the establishment of nonlinear self -excited force model in the future .