基于建模仿真的颗粒增强铝基复合材料缺陷超声检测

Ultrasonic Detection of Defects in Particle Reinforced Aluminum Matrix Composites Based on Modeling and Simulation

针对基于实验试错法进行SiC_(p)/Al复合材料缺陷超声检测效果不佳的问题,本文将超声检测建模仿真与实验测试相结合,探讨了SiC_(p)/Al复合材料偏聚缺陷的超声检测方法。基于对样品的微观观测及声学测量,建立了SiC_(p)/Al复合材料的超声检测模型,得到复合材料内部不同尺寸平底孔的仿真时域信号,经与实验结果对比,证明了所建模型的有效性。在此基础上,进一步对φ0.8mm与φ0.5mm平底孔以及φ0.8×1.6mm~φ3.2×6.4mm纯Al偏聚与SiC偏聚进行超声检测数值模拟。结果表明:对于深度相同尺寸不同的平底孔,其回波声压幅值随平底孔尺寸的增大而增大,纯Al偏聚与SiC偏聚的缺陷反射波相位相反,其幅值随偏聚缺陷尺寸的增大而增大。

Aiming at the problem that the ultrasonic testing effect of SiC_(p)/Al composite defects based on experimental trial and error method is not ideal,this paper discusses the ultrasonic testing method of SiC_(p)/Al composite segregation defects by combining ultrasonic testing modeling simulation with experimental testing.Based on the microscopic observation and acoustic measurement of the sample,the ultrasonic testing simulation model of SiC_(p)/Al composite was established,and the time domain signals of four flatbottom holes of different sizes inside the composites were obtained.The validity of the model was verified by comparing with the experimental results.On this basis,the ultrasonic testing of pure Al segregation and SiC segregation withφ0.8mm andφ0.5mm flat-bottom holes andφ0.8×1.6mm~φ3.2×6.4mm were further simulated.The results show that for flat-bottom holes with the same depth and different sizes,the amplitude of the echo sound pressure increases with the increase of the size of the flat-bottom hole.The phase of the defect reflected waves of pure Al segregation and SiC segregation is opposite,and the amplitude increases with the increase of the segregation defect size.