None
Authors: Lifu Wang (University of California, Los Angeles) , Yichi Zhang (University of California, Los Angeles) , Bhav Patel (University of California, Los Angeles) , Leonardo Araque (University of California, Los Angeles) , Steffen Tai (University of California, Los Angeles) , Ajit Mal (University of California, Los Angeles) , Fei Gao (Beihang University)
Honeycomb sandwich panels (HSP) are widely used in the aerospace industry due to their high strength to stiffness ratio. Conducting non-destructive evaluation (NDE) of HSP is a topic of great current interest. However, the geometric complexity of honeycomb core makes NDE of HSP extremely difficult. Guided ultrasonic waves are ideal for large scale testing due to its large range and high sensitivity to defects in their path. Previous research has been successful in detecting disbonds at the core-skin interface using guided waves, but few of them have focused on the detection of disbonds at the bottom interface. An improved NDE method for detecting disbonds at the top and bottom interfaces is proposed based on experimental results. By applying excitation signals for different frequencies, the responses at the top and bottom skins are compared and analyzed. The response in a specific frequency range is further studied by introducing disbond at the bottom interface. It is shown that some components of the recorded signal in specific frequency range are more sensitive to the disbond and can be related to the size of the disbond. Finally, an improvement of the conventional damage index based on propagation velocity of guided waves is provided. The results show that the optimized damage index greatly improves the resolution and flexibility of NDE on HSP.
Keywords:
How to Cite: Wang, L. . , Zhang, Y. . , Patel, B. . , Araque, L. . , Tai, S. . , Mal, A. . & Gao, F. . (2019) “An improved damage index for non-destructive testing of a honeycomb sandwich panel using guided waves”, Review of Progress in Quantitative Nondestructive Evaluation.(0).