复合材料层板超声检测缺陷评定方法分析

碳纤维增强树脂基复合材料的接触式超声检测,对大于探头直径的缺陷常采用半波高法评定大小,但各检测标准均没有对半波高法的基准波进行规定。采用不同基准波评定缺陷可能会造成缺陷评定结果不同,从而直接影响制件验收。本文采用理论分析与实际检测相结合的方法,对复合材料检测中常采用的以底面回波为基准波和以缺陷回波为基准波两种缺陷评定方法进行分析,比较了两种方法测量结果的差异,给出了复合材料层板接触式超声检测缺陷评定方法的建议。

Measurement for Ultrasonic Contact Inspection on Defect in Carbon Fiber-Reinforced Composite

When the carbon fiber-reinforced composite is inspected by ultrasonic contact method,the size of the defect is measured by the amplitude of the reflection echo.The distance between the two points can be determined as the length of the defect on one direction when the amplitude of the reflection echo comes down to half of its maximum.The reflection echo can be reflected by the defect as well as by the bottom.The effect of the choice of these two different reflection echoes on the measurement result is studied.The suggestion on how to measure the defect is also given.