The quantification of impact damage distribution in composite laminates by analysis of X-ray computed tomograms. (10th November 2017)

• Record Type: Journal Article
• Authors: Léonard, F.; Stein, J.; Soutis, C.; Withers, P.J.
• Is Part Of: Composites science and technology. Volume 152(2017)
• Page Start: 139
• Page End: 148
• Publication Date: 2017-11-10
• Subjects: Delamination -- Impact behaviour -- Non-destructive testing -- X-ray computed tomography -- Distance transform; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2017.08.034
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: One of the great strengths of X-ray computed tomography over conventional inspection methods (ultrasound, thermography, radiography) is that it can image damage in 3D. However for curved or deformed composite panels it can be difficult to automatically ascribe the damage to specific plies or inter-ply interfaces. An X-ray computed tomography (CT) data processing methodology is developed to extract the through-thickness distribution of damage in curved or deformed composite panels. The method is applied to [(0°/90°)2 ]s carbon fibre reinforced polymer (CFRP) panels subjected low velocity impact damage (5 J up to 20 J) providing 3D ply-by-ply damage visualisation and analysis. Our distance transform approach allows slices to be taken that approximately follow the composite curvature allowing the impact damage to be separated, visualised and quantified in 3D on a ply-by-ply basis. In this way the interply delaminations have been mapped, showing characteristic peanut shaped delaminations with the major axis oriented with the fibres in the ply below the interface. This registry to the profile of the panel constitutes a significant improvement in our ability to characterise impact damage in composite laminates and extract relevant measurements from X-ray CT datasets.