定距发射/接收干耦合检测探头设计与实验研究

针对固体火箭发动机(SRM)壳体复合材料在加工、存储过程中可能出现脱黏等缺陷的问题,提出了一种干耦合检测方法;并进行了实验验证。基于探头的声匹配理论,针对复合材料表面无法使用耦合剂及由此产生的超声波能量损失过大的问题,提出了采用超声变幅杆实现声匹配及能量集中功能的方法;基于探头的电匹配理论,针对探头与超声波发射/接收装置之间能量转化效率低的问题,设计了探头的匹配电路。对预制有三个不同直径缺陷的复合材料壳体通过不同的角度进行了检测实验,并将匹配后探头和未匹配探头的检测结果进行了对比。结果表明该方法能够较好的对复合材料的缺陷进行识别,经过电匹配后的探头可将检测灵敏度提高2~3倍。

Design and Experimental Study of Fixed Transmitter / Receiver Distance Transducer Based on Dry Coupling Technology

A dry coupling detection method is proposed for the defects problems such as debonding of composite materials for solid rocket motor (SRM) shell in the process of processing, storage, and it is validated through experiments. Based on the transducer acoustic matching theory, the acoustic matching and energy accumulating approaches by using ultrasonic horns stem are presented for the coupling agent unable be used on the composite material surface and large loss of ultrasonic energy. Based on the transducer of electrical matching theory, the transducer matching circuit is designed for the lower efficiency of energy conversation between the sensor and ultrasonic launchers (receivers). And then the composite materials shells with three different diameter defects are detected through experiments under different detection angles. The test results of the transducer been matched is compared with that of unmatched. It indicates that the method can be used to identify defects of composite material well and the detection sensitivity of the transducer can be improved 2 ~ 3 times after electrical matched.