Debond Localization in Honeycomb Core Sandwich Composites Using A0 Guided Wave Mode

Abstract

Honeycomb core composite sandwich structures (HCCSSs) are widely employed in the marine, defense, and aerospace industries due to their lightweight design, the superior ratio of strength-to-weight and high load-bearing capabilities. Regardless of such commendable advantages, the skin-core junctions are susceptible to debond damage from intensive loading on these structures that may threaten the safety and structural integrity of the assembly. In this study, a novel framework for the guided wave based non-destructive evaluation (NDE) of a three-dimensional HCCSS is presented. The total focusing method with full matrix capture (TFM-FMC) technique is employed to detect and quantify debond at multiple locations in the finite element model of the three-dimensional HCCSS. The fundamental antisymmetric (A0) mode of guided waves is considered for multiple debond assessments in the investigated structure. The A-scan responses of the propagating guided wave of a debond HCCSS are compared with that of a pristine model. This comparison served as a valuable damage precursor resulting from interaction effects. A substantial amplification of the modal amplitude in the case of debonded HCCSS is noticed compared to that of the pristine model. The A-scan responses captured at a location distant from the debonded zone showed little difference. The TFM-FMC algorithm based structural monitoring framework is utilized to locate and quantify the debonded zones in the HCCSS. The proposed health monitoring framework is considered to be substantially effective in the detection of debond damages in a composite sandwich structure.