Ultrasonic testing is widely used in industrial inspection. For example, phased array testing and A-scan are used to detect internal defects in parts. However, they can only detect the location of defects and it is hard to accurately detect the size of defects. Therefore, quantitative detection is a significant problem to be settled urgently. This paper presents a distributed ultrasonic testing method that a plurality of probes is arranged evenly on the detection surface. Every ultrasonic probe plays the role of transmitting probe as well as receiving probe, though processing the received signals the defect is detected. Based on the distributed ultrasonic testing method, several artificial defects were tested and the corresponding acoustic simulation model was established. The contour of the artificial defect was reconstructed through polynomial fitting method and clustering method based on the data obtained from experiments and acoustic simulation. According to the experimental results and the acoustic simulation results, the reconstructed elliptical defects and the square defects have good accuracy. The studies we have performed show that researching on the distributed ultrasonic testing method has potential application value and theoretical significance.%超声检测广泛应用于工业检测,比如超声相控阵检测法和超声A扫应用于零件内部缺陷检测.然而,这些方法可以检测出缺陷位置却很难精确地检测缺陷尺寸,缺陷定量成了急需解决并且很有意义的问题.本文提出了一种分布式超声无损检测方法,将超声探头均匀布置在检测表面,每一个超声探头可以同时发射和接收超声信号,通过对接收到的信号进行处理来重构缺陷轮廓.基于分布式超声无损检测方法,重构零件的人造缺陷并建立相应的声学仿真模型.通过多项式拟合法和聚类法分别处理实验和仿真所获得的数据并重构缺陷轮廓.实验结果和仿真结果显示重构的椭圆形缺陷和正方形缺陷具有一定的精度.结果表明分布式超声无损检测方法有潜在的应用价值和理论意义.
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