高密度聚乙烯管热熔接头的全聚焦成像实验分析

Experimental Analysis of High Density Polyethylene Butt Fusion Joints by Total Focusing Method Imaging

基于全矩阵数据捕获(FMC),利用全聚焦(TFM)成像技术,对高密度聚乙烯(HDPE)试块中不同深度(10~50 mm)的预制横通孔缺陷进行了全聚焦成像实验分析。在MATLAB软件中编写了全聚焦成像算法,并将全聚焦成像效果与超声相控阵扇形扫描成像效果进行比较。研究结果表明:全聚焦超声成像方法对于HDPE试块内部的横通孔缺陷,能够较好地实现缺陷位置的定位。在5 MHz频率探头的条件下,检测深度达到50 mm以上,深度定位误差在2 mm以内。相比于超声相控阵扇扫方法,本文方法的∅1 mm缺陷最大幅值标准差从16.8 dB降低到了7.5 dB,∅2 mm缺陷的最大幅值标准差从21.0 dB降低到了6.2 dB,有2~3倍的提升。

Based on full matrix capture data,the total focusing method(TFM)imaging technology was used to image and analyze the defects of side-drilled holes with different depths(10~50 mm)in high density polyethylene(HDPE)test block.In Matlab software,the total focusing method algorithm was coded.The TFM imaging results was compared with ultrasonic phased sector scanning data.The experimental results show that the TFM is able to locate the defects position of the side-drilled holes in the HDPE block.For the 5 MHz probe in test,the TFM algorithm can detect the defects in HDPE with depth larger than 50 mm.The defect depth location error is less than 2 mm.Compared with the ultrasonic phased sector scanning method,the maximum amplitude standard deviation of 1 mm defects(∅1 mm)is decreased from 16.8 dB to 7.5 dB,and the maximum amplitude standard deviation of 2 mm defect(∅2 mm)is decreased from 21.0 dB to 6.2 dB.The signal-noise-ration(SNR)has improved about 2~3 times.