中文摘要：

从桥梁响应识别桥面移动荷载往往出现逆问题的病态（不适定性）等共性问题。本文基于移动荷载识别理论，借助矩量法求解积分方程理论并采用整域基函数——正交勒让德多项式表达桥面移动荷载，提出了一种移动荷载识别的时域改进算法。两轴车辆多种组合工况下的常载和时变荷载数值仿真研究表明：与时域法比较，改进时域法识别桥面移动荷载时，其识别精度高、抗噪能力强，识别结果不适定性有显著改善。

英文摘要：

An improved time domain method （ITDM） is proposed for moving force identification from dynamic responses of bridges, which aims at an acceptable solution to the ill-conditioning problem that often exists in inverse problems such as moving force identification. Based on the method of moments and the theory of moving force identification, the moving forces were described as a combination of whole basis functions, i.e. orthogonal Legendre polynomials, and further were estimated by solving the new system equations developed with the basis functions. In the cases of a number of responses combination, numerical simulations for both two axles constant loads and two time-varying loads of a vehicle have been carried out and compared with the existed time domain method （TDM）. The illustrated results show that for the problem of the identification of moving force from bridge responses, ITDM has higher accuracy and robuster noise immunity, and to some extent, ITDM can offer an acceptable solution to the ill-conditioning problem.