超声探头的响应特性及暂态回波模型

发布时间：2019-01-27 16:31

【摘要】：建立检测系统的数学模型,可以更好地理解超声检测的物理本质。分析了超声波从产生、介质中传播、缺陷耦合以及接收的全过程,将缺陷回波表示为探头响应函数与缺陷响应的时域卷积。利用空间脉冲响应和基尔霍夫近似建立了超声波与平面型缺陷的耦合模型,用大平面试块底面回波和大平面响应进行反卷积求得了探头的响应函数,并详细分析了探头在不同偏置位置时不同大小缺陷响应的特点,发现缺陷回波由直达回波和边缘回波组成,直达回波和边缘回波极性相反,且直达回波的幅值远远大于边缘回波。
[Abstract]:The physical nature of ultrasonic detection can be better understood by establishing a mathematical model of the detection system. The whole process of ultrasonic wave generation, medium propagation, defect coupling and receiving is analyzed. The defect echo is expressed as the time domain convolution between the probe response function and the defect response. The coupling model of ultrasonic wave and plane defect is established by using the spatial impulse response and Kirchhoff approximation. The response function of the probe is obtained by deconvolution of the echo from the bottom surface of the large plane sample and the large plane response. It is found that the defect echo consists of direct echo and edge echo, and the polarity of direct echo and edge echo is opposite. The amplitude of direct echo is much larger than that of edge echo.
【作者单位】：西安科技大学机械工程学院;长安大学高速公路施工机械陕西省重点实验室;英国利物浦约翰摩尔斯大学通用工程研究所;西安科技大学理学院;
【基金】：国家自然科学基金项目(51074121) 中国博士后科学基金项目(2015M572653XB) 陕西省教育厅专项科学研究计划项目(15JK1455) 长安大学高速公路施工机械陕西省重点实验室开放基金项目(310825161124)资助
【分类号】：TB55

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