为了解决复合材料蜂窝夹层中变厚度构件超声波难以检测的问题,使用一种基于超声波C扫描的扫描路径规划和增益补偿法进行检测.首先对变厚度构件的扫查路径进行规划,确定探头的扫查路径;然后为保持变厚度构件不同厚度处相同的超声信号水平,对因构件厚度、表面曲率变化引起的超声信号衰减进行增益补偿,将各个点位的补偿值按坐标对应传递给超声C扫描成像模块,得到补偿后的超声C扫描图.结果表明:该方法能够准确地发现变厚度构件中的缺陷,具有较高的检测可靠性.

Composite of honeycomb sandwich structure has been widely used in the field of aerospace because of its characteristics of high strength,lightweight,sound insulation,heat insulation and other excellent performance.In order to solve the ultrasonic testing problem of this kind of structures,a trajectory planning and gain compensation method has been studied.First,the scanning path is planned to determine the trajectory of the probe.Then the attenuation of the ultrasonic signal due to the variable thickness and surface curvature of the parts is compensated in order to keep the same ultrasonic signal level of different part positions.After that the compensation value of all points should be transmitted to the C imaging module and the C image result can be obtained after scanning.The experimental results show that the defect in variable thickness parts can be well found by this method,which is of very high detection reliability,and easy to implement.