Magnetic resonance imaging of contaminated and damaged core cells in polymer composite sandwich panels

Abstract

Computed tomography magnetic resonance imaging has been successfully applied to fully detect typical aircraft hydrogen-rich liquid contaminants entrapped in honeycomb core cells of structural polymer composite sandwich panels. With the aid of Bayesian-based image processing toolbox, the quantification, identification, and discrimination of the contaminants were also rapidly accomplished. Computed tomography magnetic resonance imaging has also been auspiciously applied to accurately define the extent of crushed-core damage in liquid impregnated honeycomb cells. Presented results strengthen the potential of magnetic resonance imaging as safe, fast, reliable, and user-friendly nondestructive testing technique to all engineering fields employing composite sandwich panels as high-demanding structural members.

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

“…By following the similar procedure adopted by the authors [ 37 ], the estimated value of saline solution absorbed by the EPX-GF sample approached 20%, which is more than three times higher than the value assessed from the water absorption experiments (6%), which can be considered more precise given that the weight measurements were performed in analytical balance and that more than one specimen was monitored over a wide timespan. The more plausible explanation found for this huge difference is related to the image slice-thickness employed in this study, ranging from 1 to 2 mm, so that less than three slices were enough to sample the entire specimen thickness (3.5 mm), with one single slice comprising more than five individual fibre fabric layers of a total of twenty.…”

“…Slice thickness from 1 to 2 mm and proper interslice distance were employed to resolve most of the nuances and details of the inspected composite specimens [ 37 ]. The field of view (FOV) was determined by the two dimensions defining the imaging plane, with lower FOV values corresponding to higher digital image resolution and longer image acquisition time.…”

“…Relying on the author’s experience and expertise built during previous MRI research in composite structures [ 37 ], the present study evaluates the potential of multi-slice MRI techniques for the in vitro non-destructive inspection of defective and damaged FRP specimens immersed in simulated biofluid.…”

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

“…Less than 35 min were spent acquiring this set of images using the 2D-RARE protocol with l5 repetitions, 27 × 27 mm 2 FOV, 256 × 256 pixel matrix size (resolution of 0.1 × 0.1 mm 2 /pixel) and 14 ms echo-time. By following the similar procedure adopted by the authors [37], the estimated value of saline solution absorbed by the EPX-GF sample approached 20%, which is more than three times higher than the value assessed from the water absorption experiments (6%), which can be considered more precise given that the weight measurements were performed in analytical balance and that more than one specimen was monitored over a wide timespan. The more plausible explanation found for this huge difference is related to the image slice-thickness employed in this study, ranging from 1 to 2 mm, so that less than three slices were enough to sample the entire specimen thickness (3.5 mm), with one single slice comprising more than five individual fibre fabric layers of a total of twenty.…”

An improved bootstrap method introducing error ellipse for numerical analysis of fatigue life parameters

“…Many scholars have studied it and made some progress. Because of the characteristics of prior distribution, Bayesian bootstrap has a wide range of applications (Bollinger and van Hasselt, 2017;Tarpani and Portela, 2017).…”