Non Destructive Evaluation of Helicopter Composite Rotor Blades Using Acoustic Impact Technique A Study

摘要

In the programme CFRP laminates of 20 layers each were subjected to experimental investigations. Two laminates were subjected to different energy levels of impact, while one laminate had flaws introduced in at the time of manufacture itself. The other CFRP laminate was unimpacted and free of flaws. All the laminates were scanned using hte ultrasonic C-scan which served as a reference. Subsequently, these laminates were subjected to Acoustic Impact Testing (AIT) and the results obtained by these techniques were compared. Once a correlation was established AIT was employed to detect flaws on a helicopter composite main rotor blade. The results of the experiments show that the analysis in frequency domain is more reliable and could easily be standardized.