Ultrasonic Lamb Wave InspectionUsing Fiber Bragg Gratings
A new ultrasonic Lamb wave nondestructivetesting (NDT) system is developed in this paper.The basic ideais to use fiber Bragg gratings (FBG) sensors as acousticreceivers of ultrasonic Lamb waves.The spectral response offiber Bragg gratings (FBGs) subjected to the ultrasonic fieldhas been theoretically and numerically investigated.Takinginto account the geometrical and elasto-optic effects,the Braggeffective refractive index modulation under the ultrasonic waveaction is deduced.A transfer matrix method is used to analyzethe influence of ultrasound on the reflection spectrum of FBGs.Numerical results show that the influence of ultrasonic field ongrating spectrum is highly correlated to the ratio between theultrasonic wavelength and the grating length.Only when theratio is quite larger,the peak wavelength of reflection spectrumshifts while the shape of the grating remains unchanged.Thereason is explained by the strain variation along the grating.The results of this analysis provide useful tools for thedetermination of gage length of FBG sensor and the choice ofLamb wave frequency when the new NDT system is used fordamage detection.
FBG Lamb wave NDT reflection spectrum transfer matrix
Zhang Haiyan Sun Xiuli Qi Xuerui Liu Xiao Lu DongHui
School of Communication and Information Engineering,Shanghai University,Shanghai 200072,China School of Electronic,Information and Electrical Engineering,Shanghai Jiaotong University,Shanghai 20
国际会议
2008 China-Japan Joint Microwave Conference(2008年中日微波会议)
上海
英文
805-808
2008-09-10（万方平台首次上网日期，不代表论文的发表时间）