Inspection of Thick Composites for Near Surface Flaws

Application of Acoustic Metamaterials in Pulse-Echo Ultrasonic Evaluation of Thick Hybrid Composite Laminates

“…However, introducing thick laminated structures, mainly in marine applications, created new challenges in NDE. Although there are a few studies in the literature on the inspection of thick laminates, most of them are limited to composites with a thickness of less than 10 mm or composites that contain near-surface defects [5,11,12]. Based on a recent review by Ibrahim [1], despite considerable efforts being made on several fronts, there remains the need to develop NDE methods for the accurate inspection and characterization of internal defects in thick composites.…”

“…Fahr et al [11] used ultrasonic leaky Rayleigh waves to examine small-sized delamination (thickness less than 0.17 mm) near the surface of a composite structure, approximately 100 mm in thickness. Mouritz et al [19] studied the NDE of thick fiberglass composites using the PEUT method in specimens up to 220 mm in thickness and observed a throughthickness attenuation of 110 dB at 0.5 MHz.…”

An experimental investigation on damage mechanisms of thick hybrid composite structures under flexural loading using multi-instrument measurements

“…As composite materials find their way towards applications in primary and secondary load-bearing structures e.g., wing covers of Airbus A350 XWB, their thickness has increased significantly. Generally, any laminate with a thickness ≥ 6 mm can be considered as a 'thick' composite structure [22][23][24][25]. However, from a mechanical modeling point of view, the thick laminates are classified based on a span-to-thickness ratio of less than 20.…”