用于裂纹方向识别的超声散射系数分析方法研究

发布时间：2018-03-30 10:59

本文选题：散射系数　切入点：相控阵探头　出处：《声学学报》2016年01期

【摘要】：本文主要利用超声相控阵技术进行了裂纹方向识别研究。首先,对线性超声相控阵探头采集的全矩阵数据进行了全聚焦成像,确定缺陷的位置。然后将线性阵列划分为若干子阵列,研究了缺陷位置处子阵列的散射系数分布,从中提取出缺陷的方向信息。在此基础上,研究了子阵列参数选择(子阵列包含晶片数及相邻子阵列间隔晶片数)及探头位置对裂纹方向识别的影响。通过对散射系数分布图中提取的3个特征指标,角度测量误差、角度分辨率及相对脊带宽度,进行主成分分析,评价了子阵列参数设置(如子阵列包含晶片数及相邻子阵列间隔晶片数)对裂纹方向识别的影响,优化出最佳的检测位置及子阵列参数设置。仿真和检测实验结果表明,当相邻子阵列间隔晶片数为1,包含晶片数为11个时,可以利用超声散射系数分布进行裂纹方向的准确测量,测量误差小于2%。
[Abstract]:In this paper, we mainly use ultrasonic phased array technology to identify the crack direction. Firstly, the full matrix data collected by linear ultrasonic phased array probe are fully focused. Then the linear array is divided into several sub-arrays, and the scattering coefficient distribution of the defect position virgin array is studied, from which the direction information of the defect is extracted. The influence of sub-array parameter selection (the number of chips and the number of adjacent sub-array spacers) and the position of probe on the identification of crack direction is studied. The angle measurement error is obtained from the three characteristic indexes extracted from the scattering coefficient distribution. The angle resolution and relative ridge width are analyzed by principal component analysis (PCA), and the effects of sub-array parameters (such as the number of chips contained in the sub-array and the number of adjacent sub-array spacers) on the identification of the crack direction are evaluated. The results of simulation and test show that when the number of adjacent sub-arrays is 1 and the number of chips is 11, The ultrasonic scattering coefficient distribution can be used to accurately measure the crack direction, and the measurement error is less than 2.
【作者单位】：北京工业大学机电学院;北京工业大学北京市精密测控技术与仪器工程技术研究中心;中国特种设备检测研究院;
【基金】：国家自然科学基金(51075012,11272017) 北京市自然科学基金(1122005) 质检公益项目(201310156)资助
【分类号】：O346.1;O426.9

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