Phased array B-scan acoustic field simulation of aluminum extrudate FSW welds with complex shapes

Because the section of aluminum alloy extrudate used in high-speed train is complex, lots of structural echoes and noise will be received when using array ultrasound to detect the flaws in friction stirring welds (FSW). Therefore, phased array acoustic field model and acoustic rays propagation model were introduced to simulate the acoustic field pressure distribution and the sound beams propagation paths. According to the simulation results, the appropriate incident angle of sound beam, depth of focus and other parameters were determined. Meanwhile the echoes in the B-scan images can be predicted and it will be helpful to predict the feature points in the B-scan images, as a result, the analysis and defect detection of the FSW welds will become convenient.