声波检测穿透信号波形变化规律和量化的探讨

超声检测应用声学信息(声时、波幅、频率、波形)来判断被测介质的物性。前三个信息均有定量或半定量数学表达式为依据,波形还无法有定量解释。为寻求波形的变化规律,采用模型试块进行试验。试验结果证实:符合声学边界条件的均匀介质,接收信号的波形基本与发射的子波具有相似性,当介质中存在异物(缺陷)接收信号发生变异,可由斯奈尔定律、叠加定律作出解释,总结出一定规律,提出定量的量化方法。

DISCUSSION ON THE VARIATION AND QUANTIFICATION OF PENETRATING SIGNAL WAVEFORM IN ACOUSTIC WAVE DETECTION

For supersonic detection,the physical property of the measured media can be identified by using such kinds of acoustic information as the acoustic time,amplitude,frequency and waveform.The first three kinds of information can be measured based on quantitative or semi-quantitative mathematical expression,whereas the last one cannot be quantitatively interpreted.In order to study the variation of the waveform,the authors made a test by using the model test block.The test results show that the waveform of received signal is basically similar to that of the launching wavelet for the homogeneous media,which is consistent with acoustic boundary conditions.The mutation of received signal can result from the foreign body(defect) existent in the media.It can be explained based on the laws of refraction and superposition,so as to summarize some regularities and propose a quantitative method for quantification.