摘要
桥梁影响线(IL)被广泛用于动态称重、结构评估、损伤识别等领域,如何从桥梁实测响应中准确提取桥梁影响线至关重要。为此,提出一种自适应拟合算法,用于从车辆过桥响应中提取高精度、准静态的桥梁影响线。从多车轴对桥梁的作用机理出发,通过矩阵运算获取桥梁初始影响线。随后,采用自适应拟合算法来消除初始影响线中的波动干扰成分,从而提取高精度、准静态的桥梁影响线。开展静载和移动荷载模型桥试验,以静载实测影响线为基准,与移动荷载试验所提取的影响线作对比,验证文中自适应拟合算法的可行性。最后,通过与既有影响线提取方法进行比较,深入探讨了多种算法在波动性、精确性和计算速度上的优劣,验证了自适应拟合算法在提取桥梁影响线上的优势。研究结果表明:桥梁实测响应中包含了静态成分和波动成分,自适应拟合算法可较好地提取准静态桥梁影响线。该算法可根据原始响应的波动程度自动选取合适的数据段进行拟合,通过调节参数λ达到平滑的效果,同时保留数据局部信息。所提取的影响线不仅在精度上较既有方法存在一定优势,计算速度也较为理想,可在2~3次迭代后达到较高精确度。提出的基于自适应拟合的桥梁影响线提取方法为影响线的广泛应用奠定了基础。
Bridge influence lines(ILs)are widely used in dynamic weighing,structure assessment,and damage identification.Extracting accurate bridge ILs from measured bridge responses is an essential issue.This paper proposed a self-adaption fitting algorithm for extracting accurate bridge ILs from bridge response.This method analyzed the mechanism of the multi-axle vehicle crossing the bridge and obtains the initial IL by matrix calculation.Then,a self-adaption fitting algorithm was used to eliminate the fluctuating disturbance in the initial IL and extract high accuracy and quasi-static bridge ILs.Static and moving load tests of the model bridge were carried out.The ILs measured from the static test were compared with the ILs extracted from the moving load tests to verify the feasibility of the proposed method.Finally,the performance of the algorithms was discussed in depth by comparing them with the existing IL extraction methods.The advantages of the proposed method were verified in terms of fluctuation,accuracy,and computational speed.The results show that the method can better extract quasi-static bridge ILs from the bridge response containing static and fluctuating components.The selfadaptive fitting method can automatically select suitable data segments for fitting according to the fluctuation of the original response.By adjusting the parameterλ,it achieves a smoothing effect while preserving data details.Moreover,this method not only has certain advantages over the existing methods in terms of accuracy,but also can achieve high accuracy after 2~3 iterations with high speed.The results can provide a novel method for bridge IL extraction,which lays the foundation for its application.
作者
石爽
王灿
王宁波
SHI Shuang;WANG Can;WANG Ningbo(Anhui Sanlian Group Postdoctoral Workstation,Hefei 230601,China;School of Civil Engineering,Central South University,Changsha 410075,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2024年第5期1909-1918,共10页
Journal of Railway Science and Engineering
基金
安徽省自然科学基金资助项目(KJ2020A0800)
安徽省普通高校交通信息与安全重点实验室项目(JTX202304)
湖南省自然科学基金资助项目(2021JJ30840)。
关键词
桥梁影响线
移动荷载试验
自适应拟合
迭代拟合
信号处理
bridge influence line
moving load testing
self-adaption fitting
iterative fitting
signal processing
