Detection and Imaging of Damages and Defects in Fibre-Reinforced Composites by Magnetic Resonance Technique

Abstract

Defectively manufactured and deliberately damaged composite laminates fabricated with different continuous reinforcing fibres (respectively, carbon and glass) and polymer matrices (respectively, thermoset and thermoplastic) were inspected in magnetic resonance imaging equipment. Two pulse sequences were evaluated during non-destructive examination conducted in saline solution-immersed samples to simulate load-bearing orthopaedic implants permanently in contact with biofluids. The orientation, positioning, shape, and especially the size of translaminar and delamination fractures were determined according to stringent structural assessment criteria. The spatial distribution, shape, and contours of water-filled voids were sufficiently delineated to infer the amount of absorbed water if thinner image slices than this study were used. The surface texture of composite specimens featuring roughness, waviness, indentation, crushing, and scratches was outlined, with fortuitous artefacts not impairing the image quality and interpretation. Low electromagnetic shielding glass fibres delivered the highest, while electrically conductive carbon fibres produced the poorest quality images, particularly when blended with thermoplastic polymer, though reliable image interpretation was still attainable.

MRI Applications and Research in Materials Science

“…The utilization of MRI is particularly beneficial in the examination of fiber-reinforced composites. MRI's capacity to function regardless of damage orientation and its significant electromagnetic wave penetration power is crucial in this context [8]. The resolution provided by MRI is noteworthy, with a range of 25 to 100 μm.…”

Concrete CFRP-Reinforced Beam Performances, Tests and Simulations

“…Monitoring the beams' behavior under different loadings and investigating damage using non-destructive evaluation techniques (NDTs) is a critical study topic [36][37][38][39][40][41]. NDTs were categorized into five groups [41]: (1) visual inspection [41]; (2) acoustic wave-based techniques [36], like acoustic emission (AE) [36,42], impact-echo [36,41,42], ultrasonic testing [40], and acoustic-laser techniques [42]; (3) optical techniques like infrared thermography, digital shearography [43] and terahertz testing; (4) imaging-based techniques like microwave NDTs [44], (5) electromagnetic methods like magnetic resonance [45], and electro-mechanical impedance [37]. Data fusion [38] is also utilized because it combines data from different sources.…”