基于矩量法的桥梁移动车载识别试验研究

EXPERIMENTAL STUDY ON IDENTIFICATION OF MOVING VEHICLE LOADS ON A BRIDGE BASED ON MOMENTS METHOD

基于矩量法和移动荷载识别理论,采用整域基函数———正交勒让德多项式表达桥面移动车载,从车致桥梁弯矩响应识别桥面移动车载,提出了一种时域移动荷载识别改进方法(ITDM)。利用试验测量的车致桥梁弯矩响应时程数据重点研究了几个主要参数对ITDM的影响,这些参数包括:基函数数量、模态数、测点数及测点位置和运行时间等,同时与时域法(TDM)进行了对比研究。试验研究结果表明:ITDM性能与TDM相若,但ITDM更以适应性强和省时而优于TDM,这对于桥梁移动荷载的现场在线准确识别非常有利。

An improved time domain method(ITDM) is proposed for identification of moving vehicle loads on a bridge based on both moments method and theory of moving force indentification.The moving vehicle loads are expressed in terms of orthogonal Legendre polynomials and then estimated from the bridge bending moment responses caused by the moving vehicles on the bridge.By using the measured bending moment responses of a bridge model made in laboratory,the authors investigate effect of various paramenters on the ITDM.These parameters include Legendre basis function number,mode number,measured stations and CPU executive time of the ITDM.Further,the ITDM is compared with the existing time domain method(TDM).Experimental study results show that the ITDM has good properties almost same as those of the TDM,but it can save the identification CPU time as well as it has a better flexibility than the TDM.This is beneficial to real time analysis of moving force online identification.