考虑桥路面粗糙度的移动体参数识别

Parameter identification of moving vehicles considering road roughness of bridge

基于虚拟变形(VDM)方法中移动动态影响矩阵的概念,利用双自由度质量-弹簧阻尼模型模拟移动车辆,系统推导和阐述了车-桥耦合系统中粗糙路面上移动体参数的识别方法。以移动体参数的修正因子为优化变量,通过最小化桥体结构实测响应和计算响应的平方距离进行识别,识别精度高,对噪声鲁棒性强,且较少的传感器就能识别多个移动体参数。利用移动动态影响矩阵,每步优化中无需时时重构系统参数矩阵,计算效率高。利用一个三跨连续梁模型验证该方法的有效性,在5%的噪声影响下,利用一个传感器可以准确地识别多个移动体参数和移动荷载。此外,通过比较平坦路面与粗糙路面上的移动体参数的识别方法和结果,结合车体参数的灵敏度分析,说明了路面粗糙度、移动体参数对结构响应的影响及不同情况下参数识别中优化变量的选取原则。

Using the concept of dynamic moving influence matrix in VDM,a moving vehicle identification method in vehicle-bridge coupled system is derived and elaborated,and for which the road roughness is considered.The vehicle is simulated by a two degree of freedoms mass-spring vehicle model.In this method,vehicle parameters are taken as the variables and then optimized by minimizing the square distance between the measured responses of the bridge and its estimated responses with high identification accuracy.The method is robust to noise and moreover requires fewer sensors than that needed in moving loads identification methods.During the optimization,the repetitive construction of the variant system matrix can be avoided by the utilization of the dynamic moving influence matrix and thus the optimization efficiency is high.A numerical example of a three-span beam with rough surface is used to verify the proposed method,in which the multiple vehicle parameters and moving forces can be identified successfully by one sensor with the pollution of 5% Gaussian noise.In addition,the identifications of vehicle parameters on respective ideal smooth road surface and rough surface are discussed.Via the sensitivity analysis of the vehicle parameters,it further states the influence of the road roughness and vehicle parameters on the structural response.At last it gives the selection suggestion of the optimization variables in different identification cases.