导航

ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2014, Vol. 35 ›› Issue (8): 2348-2354.doi: 10.7527/S1000-6893.2013.0463

• Material Engineering and Mechanical Manufacturing • Previous Articles     Next Articles

Quantitative Characterization Test of Fastening Hole Delamination in Composites with Laser Ultrasonics

ZHOU Zhenggan, SUN Guangkai, CHEN Xiucheng, WANG Jie   

  1. School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China
  • Received:2013-09-21 Revised:2013-11-06 Online:2014-08-25 Published:2013-11-14
  • Supported by:

    International S&T Cooperation Program of China (2013DFR70780); Aeronautical Science Fundation of China (20120951015)

Abstract:

An effective method for the detection of fastening hole delamination in composite aeronautical structures is proposed. Tests for the quantitative characterization of drilling-induced delamination in composites are conducted based on the laser ultrasonic technique. A specimen of carbon fiber reinforced plastic material is prepared, and the fastening holes are processed. Ultrasonic waves are generated by the thermo elastic effect of the material as it is illuminated by a pulse laser whose parameters are selected according to the principle of laser ultrasonic generation in composites. Ultrasonic signals that could be used to characterize the subsurface drilling-induced delamination are extracted. Major factors that might influence the characterization precision of the delamination are analyzed, and it can be seen that the dimension of the laser spot size (1-5 mm) has little influence on the characterization of the delamination. Typical C-scan testing of the specimen with laser ultrasonic technique is accomplished based on the transmission and pulse echo method, and the features of morphology, dimension and position of the drilling-induced delamination are obtained. The results prove that based on the advantages of the laser ultrasonic technique (e.g. non-contact generation and detection, high resolution), the drilling-induced delamination in composite aeronautical structures can be characterized effectively by measuring the wave reflection and attenuation induced by the delamination.

Key words: composites, nondestructive testing, drilling, delamination, laser ultrasonics

CLC Number: