Characterization of concrete damage using a non-contact nonlinear ultrasonic technique
In this paper,the feasibility of a fully non-contact second harmonic generation(SHG)technique using a pair of air coupled ultrasonic transducers is investigated for the evaluation of surface cracks of concrete beams subjected to the bending load.The reliability of developed technique is verified through a comparison with the nonlinear ultrasonic measurements based on contact-type sensors.The quadratic nonlinear parameter is found to have a monotonically increasing trend with the growth of concrete crack,and the increase of nonlinear parameter corresponding to the largest crack is about 7 times the value for concrete specimen in intact state.In contrast,the variation of a typical linear parameter namely the phase velocity from the intact state to the largest crack is only about 27%.The difference as high as one order of magnitude validates the high sensitivity of developed air-coupled SHG technique.With consideration of the easily removable characteristic of air-coupled ultrasonic measurements,the developed SHG technique could be promising for the large-scale quality control of concrete structure in engineering practice.
nonlinear ultrasonic air-coupled transducer Rayleigh waves second harmonic generation concrete crack
Chenglong Yang Jun Chen
Department of Civil Engineering,Beihang University,Beijing,China
国际会议
The 7th World Conference on Structural Control and Monitoring(7WCSCM)(第七届结构控制与监测世界大会)
青岛
英文
1442-1448
2018-07-22（万方平台首次上网日期，不代表论文的发表时间）