基于精细积分的桥梁移动荷载识别精度分析

为了识别作用于桥梁结构的移动荷载并对识别的敏感性进行分析,比较各参数对识别结果的影响,首先有效地将桥梁结构振动微分方程转化为精细积分方法的一般形式,进而得出荷载识别精细积分方法的HPD-S格式;基于Matlab仿真技术,重点讨论测量噪声、模态数、车速及采样频率等几个主要参数对识别结果的影响。仿真算例表明,该识别方法对模态数不敏感,但对采样频率敏感性较高,车速与测量噪声是影响荷载识别精度的主要因素。通过选择适当的参数,该方法可以有效地识别桥梁结构的移动荷载,从而为工程应用提供技术指导。

Precision analysis for dynamic moving load identification of bridge structure based on precise integration method

The vibration differential equation of bridge structure is converted into the general format of PIM(precise integration method) in order to identify the moving load of bridge structure and to analyse the effect of various parameters on the identification.The HPD-S format of PIM for moving load identification is then obtained.by using Matlab numerical technique,the effects of some primary parameters,such as measurement noise,mode number,vehicle speed and sampling frequency,are discussed.Numerical results show that the method is not sensitive to the number of modes,whereas it is sensitive to sampling frequency.And the measurement noise and vehicle speed are identified as the two main obstacles leading to erroneous results.With a good choice of these parameters,it can identify moving load effectively,which is a good guide for engineering application.