考虑初始条件影响的移动荷载识别稀疏正则化方法  

Sparse regularization based moving force identification under unknown initial conditions

作　　者：潘楚东 余岭 刘焕林[1] 骆紫薇 PAN Chu-dong;YU Ling;LIU Huan-lin;LUO Zi-wei(School of Mechanics and Construction Engineering,Jinan University,Guangzhou 510632,China;MOE Key Lab of Disaster Forecast and Control in Engineering,Jinan University,Guangzhou 510632,China)

机构地区：[1]暨南大学力学与建筑工程学院,广东广州510632 [2]暨南大学重大工程灾害与控制教育部重点实验室,广东广州510632

出　　处：《振动工程学报》2018年第5期734-743,共10页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51678278;51278226)

摘　　要：利用桥梁实测响应反演桥面移动荷载是桥梁工程的研究热点之一。但既有移动荷载正则化识别方法没有考虑未知初始条件的影响。针对此问题,基于稀疏正则化技术提出了一种新的移动荷载识别方法。首先分别采用冗余字典与模态空间描述移动荷载与初始条件,计算各个荷载与初始条件分量引起的响应,归一化构造用于表达响应的像字典。然后利用像字典对响应进行稀疏分解,其结果即可用于估算未知移动荷载。最后采用数值仿真算例评价所提方法的可行性与有效性,并通过实验室搭建的车-桥系统模型对新方法进行实验验证。研究结果表明:未知初始条件下,所提方法能有效地识别移动荷载。Moving force identification(MFI)from measured responses of bridges is a hot topic in bridge engineering.Current regularization-based MFI methods do not consider any influences from unknown initial conditions.In this study,a novel method is proposed for solving the MFI problem under unknown initial conditions based on sparse regularization.Firstly,the redundant dictionary and modal space are used for expressing moving forces and initial conditions,respectively.Responses induced by each component of moving forces and initial conditions are calculated and used for forming an image dictionary via normalization.The measured responses are decomposed by the image dictionary and then the decomposed results are used for estimating the moving forces.Finally,numerical simulations are used for assessing the accuracy and feasibility of the proposed method.A vehicle-bridge system model is then designed and fabricated in laboratory.A series of responses of a beam bridge subjected to moving vehicles are measured and used to verify the proposed method.The results show that the proposed method can identify the moving forces under unknown initial conditions.

关 键 词：移动荷载识别 桥梁 初始条件 稀疏正则化 稀疏分解 

分 类 号：TU311.3[建筑科学—结构工程] U441.2[建筑科学—桥梁与隧道工程]