基于部分散射系数矩阵的缺陷识别方法研究

Research on defect recognition method based on partial scattering coefficient matrix

为了在相控阵超声成像检测时实现缺陷的定性分析,采用部分散射系数矩阵表征传感器采集到的部分散射场信息,并利用部分散射系数矩阵图进行缺陷识别。以相控阵超声全阵列采集获取到的全矩阵数据为基础,结合声波传播过程的衰减性,采用逆向补偿的方法将全矩阵数据补偿到以缺陷为中心的同一圆周上,以此获取缺陷的部分散射信息,并采用部分散射系数矩阵来表征。通过分析缺陷的部分散射系数矩阵图特征,对缺陷进行定性分析和判别。采用此方法对两种典型的缺陷进行仿真实验,结果显示,部分散射系数矩阵图不仅对圆孔和裂纹两类不同缺陷表现出差异性,对同类型不同尺寸和不同角度的裂纹也有明显的不同之处,表明利用该方法可实现缺陷的定性识别。

In order to realize the qualitative analysis of defects in ultrasonic imaging of phased array, partial scattering coefficient matrix is used to characterize the partial scattering field information collected by the sensor, and the defect identification is performed by the partial scattering coefficient matrix chart. Based on the full matrix data acquired by full matrix capture of phased array ultrasound and combined with acoustic attenuation of the propagation process, the partial scattering information of defects is obtained by using the inverse compensation method to compensate the full matrix data to the same circle with the defect as the center, and the partial scattering coefficient matrix is used to represent the partial scattering information. By analyzing the characteristics of the partial scattering coefficient matrix graph of the defect, the defect can be qualitatively analyzed and distinguished. Simulation experiment is carried out by using this method for two typical defects, and results show that obvious differences not only exist in the partial scattering coefficient matrices of both hole and crack defects, but also exist in cracks with different sizes and different angles. It is therefore proven that the method can realize the qualitative identification of defects.