Research on An Inspection Method for De-bond Defects in Aluminum Skin-Honeycomb Core Sandwich Structure with Guided Waves

摘要

In order to increase the ultrasonic inspection speed of skin honeycomb core sandwich structure, the application of guided waves in this field was researched on. The characteristics of guided waves was stated, the propagation of guided waves in the skin honeycomb core sandwich structure was analyzed. Guided wave mode was selected in term of signal amplitude relative change dependent on the wave structure theory. Through short time frequency transform time frequency analysis, the frequency change of signal due to defects was researched. Best line scan distance was determined based on the signal in different position. It is testified that A0 mode has a better sensitivity on de-bond defect. The de-bond defect can be inspected through the comparison of amplitude. Although some of energy would leak into the core, the guided waves can travel over longer distance which results that the guide wave line scan has quicker inspection speed.