In structural health monitoring(SHM),the measurement is point-wise but structures are continuous.Thus,input estimation has become a hot research subject with which the full-field structural response can be calculated with a finite element model(FEM).This paper proposes a framework based on the dynamic stiffness theory,to estimate harmonic input,reconstruct responses,and to localize damages from seriously deficient measurements.To begin,Fourier transform converts the dynamic equilibrium equation to an equivalent static one in the frequency domain,which is under-determined since the dimension of measurement vector is far less than the FEM-node number.The principal component analysis has been adopted to"compress"the under-determined equation,and formed an over-determined equation to estimate the unknown input.Then,inverse Fourier transform converts the estimated input in the frequency domain to the time domain.Applying this to the FEM can reconstruct the target responses.If a structure is damaged,the estimated nodal force can localize the damage.To improve the damage-detection accuracy,a multi-measurement-based indicator has been proposed.Numerical simulations have validated that the proposed framework can capably estimate input and reconstruct multi-types of full-field responses,and the damage indicator can localize minor damages even with the existence of noise.

Yixian LI;Limin SUN;Wang ZHU;Wei ZHANG

Department of Bridge Engineering,College of Civil Engineering,Tongji University,Shanghai 200092,China;State Key Laboratory of Disaster Reduction in Civil Engineering,Department ofBridge Engineering,College of Civil Engineering,Tongji University,Shanghai 200092,China;Shanghai Qizhi Institute,Shanghai 200092,China;Sichuan Highway Planning,Survey,Design,and Research Institute Ltd.,Chengdu 610000,China;Fujian Key Laboratory of Green Building Technology,Fujian Academy of Building Research,Fuzhou 350028,China

结构与土木工程前沿

[1]Yixian LI;Limin SUN;Wang ZHU;Wei ZHANG-.A dynamic stiffness-based framework for harmonic input estimation and response reconstruction considering damage)[J].结构与土木工程前沿,2022(04):448-460

capably

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