Ultrasonic characterization of ultra-thin elastic layer using retrieve function
Ultrasonic characterization of ultra-thin elastic layer using retrieve function出 版 物:《Chinese Journal of Acoustics》 (声学学报(英文版))
年 卷 期:1998年第17卷第4期
页 面:329-340页
学科分类:07[理学] 082403[工学-水声工程] 08[工学] 070206[理学-声学] 0824[工学-船舶与海洋工程] 0702[理学-物理学]
摘 要:Using frequency domain retrieve function, a method is presented for characterizing ultra-thin plate by low frequency ultrasound. Ultra-thin means that the thickness of specimen is much less than the wavlength. The throughtransmission retrieve function is examined in detail. In conjunction with the method of least squares, the amplitude spectrum, phase spectrum and complex spectrum are all used to determine the best estimation. An analysis of some typical sources of the estimate deviation is presented. The sensitivities of the retrieve function to acoustical parameters and its significance in the propagation of errors have been derived and well *** experimental study the technique is employed to characterize the brass sheets ranging from 25.4μm to 152.4 pm with a broadba-nd 2 MHz transducer. It is observed that the agreement between the nominal value and the estimation is excellent.