移动荷载识别的适用性研究

桥梁移动荷载识别技术的适用性是决定其能否直接应用于现场桥梁荷载在线识别的关键因素。基于矩量法和移动荷载识别理论,采用整域基函数表达桥面移动车载,提出了一种时域移动荷载识别改进方法(ITDM)。分别选用正交勒让德多项式和傅立叶级数作为基函数,形成两种改进算法(LITDM和FITDM),通过仿真及试验验证所提方法的正确性及可行性,并从基函数数量和运行时间两方面与时域法(TDM)进行对比研究。仿真及试验研究结果表明:LITDM、FITDM性能与TDM相近,但ITDM灵活性更强,其中以FITDM计算效率最高,适用性最强,LITDM次之,这对于桥梁移动荷载的现场在线准确识别非常有利。

APPLICABILITY STUDY ON MOVING LOAD IDENTIFICATION

The applicability of moving load identification method is a crucial parameter, which can be used to determine whether the method can be adopted in the field or not. Based on the method of moments and the theory of moving load identification, an improved time domain method (ITDM) is proposed for the identification of moving vehicle loads. The moving loads are expressed in terms of a series of basic functions, such as orthogonal Legendre polynomials and Fourier series, and are estimated by solving the new system equations developed based on the basic functions. Some numerical simulations and experiments in laboratory were carried out, which aimed at conducting a comparative study and evaluating the effect of the basic function number and the CPU executive time on the ITDM. The illustrated results show that the ITDM almost has as good potentials as the time domain method (TDM), but it can save the CPU executive time as well as with a better flexibility and applicability when compared with the TDM, especially when the Fourier series are adopted as the basic functions. This is beneficial to the real time analysis of moving load identification in field.