Figure 18 - uploaded by José R. Tarpani
Content may be subject to copyright.
Four MR tomographic images of sample S8 images (multiple-slice mode) taken from evenly spaced X-planes along the sample thickness, showing the inside of the sandwich panel containing crushed-core damages. MR: magnetic resonance.
Source publication
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 cont...
Similar publications
The significance of this study lies in the importance of (1) nondestructive testing in defect studies and (2) securing the reliability of breast cancer prediction through thermal analysis in nondestructive testing. Most nondestructive tests have negative effects on the human body. Moreover, the precision and accuracy of such tests are poor. This st...
![Fig. 7. Metallic material available in the middle parts of the column [4]](profile/Rueya-Kilic-Demircan/publication/324109160/figure/fig3/AS:648935282601985@1531729636072/Metallic-material-available-in-the-middle-parts-of-the-column-4_Q320.jpg)
![Fig. 8. Damage assessment using IR camera [20]](profile/Rueya-Kilic-Demircan/publication/324109160/figure/fig4/AS:648935282589697@1531729636116/Damage-assessment-using-IR-camera-20_Q320.jpg)
![Fig. 9. Damage assessment in the brick wall using IR camera [20]](profile/Rueya-Kilic-Demircan/publication/324109160/figure/fig5/AS:648935282581505@1531729636146/Damage-assessment-in-the-brick-wall-using-IR-camera-20_Q320.jpg)
Historic structures are social and cultural heritage for the land they are built on. To protect this heritage and to preserve it for the generations to come are among the most important responsibilities of nations. However numerous historical structures are found in Turkey, the awareness around nondestructive maintenance processes which will keep t...
The bolt support quality of coal roadways is one of the important factors for the efficiency and security of coal production. By means of a self-developed technique and equipment of random non-destructive testing, non-destructive detection and pre-warning analysis on the quality of bolt support in deep roadways of mining districts were performed in...
Citations
... The potential of magnetic resonance imaging (MRI) as a NDE technique has been successfully applied for detection, quantification, identification and discrimination of various liquid contaminants trapped inside the honeycomb core cells of aircraft-grade structural polymer composite sandwich panels. It has also been applied to accurately define the extent of crushed-core damage in liquid impregnated honeycomb cells [14]. The potential of multi-slice MRI is studied for in-vitro NDE of defective and damaged FRP specimens immersed in water-based saline solution simulating biofluids. ...
Polymer-based Glass composite cylindrical structures consisting of multi-layered configuration for special applications were tested with low magnetic field nuclear magnetic resonance (NMR) technique. Relaxation times of chemical species at the interface of adhesive bond were investigated. Studies indicated that the single-sided NMR inspection of such composite structures is a feasible non-destructive evaluation technique to study the adhesive bond interface properties. Results of single-sided inspection over cylindrical surface using low field NMR having magnetic field strength of 0.3 T (12.88 MHz RF frequency) indicated distinct signal intensity values for different constituent materials. Interfacial defects such as de-bond and voids were detectable through the multi-layers of the structure. Overlapping defects at multiple interfaces have no bearing on the signal as well as relaxation times of constituent materials.
... 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. ...
... 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. ...
... 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. ...
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.
... 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. ...
... 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. ...
... 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. ...
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.
... 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). ...
Purpose
The purpose of this paper is to introduce error ellipse into the bootstrap method to improve the reliability of small samples and the credibility of the S-N curve.
Design/methodology/approach
Based on the bootstrap method and the reliability of the original samples, two error ellipse models are proposed. The error ellipse model reasonably predicts that the discrete law of expanded virtual samples obeys two-dimensional normal distribution.
Findings
By comparing parameters obtained by the bootstrap method, improved bootstrap method (normal distribution) and error ellipse methods, it is found that the error ellipse method achieves the expansion of sampling range and shortens the confidence interval, which improves the accuracy of the estimation of parameters with small samples. Through case analysis, it is proved that the tangent error ellipse method is feasible, and the series of S-N curves is reasonable by the tangent error ellipse method.
Originality/value
The error ellipse methods can lay a technical foundation for life prediction of products and have a progressive significance for the quality evaluation of products.
In this study a representative sandwich panel is investigated statically in two different configurations under similar bending loads. In one configuration serrations are introduced in the honeycomb core while the other one has un-modified core. Three-point bend test (TPBT) has been performed on both configurations through Finite Element Analysis (FEA) technique using ANSYS Workbench considering American Society for Testing and Materials (ASTM) standards. In both configurations the same aluminium honeycomb core is modelled having an adhesive layer in between adjacent foils to simulate actual scenario instead of relying on the block properties. Honeycomb core offers highest strength in its thickness (T) direction or the z -direction by virtue of its shape. Any distortion in the shape of the honeycomb adversely affects its strength. During bending the honeycomb core witnesses multidirectional forces consequently leading to distortion or crumpling. The serrations in the structure allow bending of the honeycomb core with minimal loss of strength by limiting the deformation to a specific region consequently preserving the shape as well as the strength of the honeycomb core. The results of both samples are compared with respect to deflection, strain and reaction force. It proves that serrated core is more favourable to be used in bent or curved sandwich panels.
