Abstract
Mechanical Engineering Fuchinobe 5-10-1, Chuo, Sagamihara, Kanagawa, 252-5258The purpose of this study is to evaluate interaction of low-frequency So-mode Lamb wave and rectangular-type defects on a 6-mm-thick steel plate. In order to discuss the effect of width of defect on amplitude of wave reflected with the defects, two dimensional FDTD method and experiment were performed. In calculation, in the case that the defect width is less than 0.4 times wavelength of So-mode Lamb wave, amplitude of wave reflected from the defects depended on width of the defects as well as depth, since an interaction of reflection wave from wall of defect at incident side of Lamb wave and refraction wave at transmitted side. In calculation and experiment, amplitude of wave reflected with defect on the 6-mm-thick steel plate increased with cross-sectional area of the defect. However, the reflection coefficients were slightly smaller than cross-sectional area ratio of defect. It may be due to mode conversion at defect.
