本文通过计算超声波遇到球状缺陷时三种假定传播路径的理论声时,对比实测声时表明实际路径为沿圆切线传播。改变球状缺陷体积分析超声波信号的变化规律,从拟合曲线可以看出,缺陷体积较小时,虽然实测声时变化不大,但对应缺陷直径变化较大,因此估算缺陷体积时,会因较小的测试误差而产生较大的计算误差。 In this paper, by calculating the theoretical sound of the three hypothetical propagation paths when the ultrasonic wave encounters spherical defects, comparing with the actual measured sound shows that the actual path propagates along the circular tangent. Change the spherical defect volume analysis of ultrasonic signal variation law, we can see from the fitting curve, the smaller the volume of the defect, although the actual measured acoustic little change, but the corresponding defect diameter larger changes, so the estimated defect volume, due to smaller The test error and a larger calculation error.