Synchrotron Radiation X-ray Micro-computed Tomography Research Articles

Microscopic deformation mechanisms of unidirectional fiber bundles under transverse compressive stresses

The high-performance filament yarns, such as carbon fiber yarn, glass fiber yarn, and Kevlar fiber yarn, have characterized as unidirectional，high parallel filament in fiber bundle. However, due to the difficulties in statistically analyzing the micro-structural characteristics of high-performance fiber bundles comprising of thousands of filaments, Nylon (PA6) filament yarns were chosen as the substitute of high-performance fiber bundles to study the deformation micro-mechanisms of fiber bundles under transverse compressive stresses. In order to evaluate the effects of different compressive stresses on the deformation properties, the synchrotron radiation X-ray micro-computed tomography (micro-CT) was used to obtain cross-section images of the fiber bundle during the compression testing. In particular, the influences of compressive stress on the fiber volume fraction, fiber distribution, fiber contact, and fiber orientation were studied. Results indicate a strong dependence of the microstructure of fiber bundles on the compressive stress.

Nondestructive Three-Dimensional Observation of the Influence of Zirconium Inclusions in Laser-Irradiated Fusion-Spliced Optical Fiber on Core Structure Changes Using Synchrotron Radiation X-ray Micro-Computed Tomography

In this paper, we describe a nondestructive method of observing changes in the microstructure of optical fibers subjected to CO2 laser irradiation for optical fiber splicing using synchrotron radiation micro-computed tomography (CT). In particular, we evaluated a method of enhancing the contrast between a GeO2-doped optical fiber core and a silica cladding by performing CT observations of the X-ray energy around the Ge-K absorption edge. Specifically, procedures for extracting a GeO2-doped core from a three-dimensional image of optical fibers by the cluster labeling method are proposed and evaluated. The approach enabled us to observe how inclusions at the optical fiber splicing interface influence the optical fiber core structure. We also expect this observation method to be used for improving such aspects of laser processing performance as insertion loss and mechanical strength for recently developed optical fibers.

Segmentation of Synchrotron Radiation micro-Computed Tomography Images using Energy Minimization via Graph Cuts

The research on applications of segmentation algorithms to Synchrotron Radiation X-Ray micro-Computed Tomography (SR-μCT) is an open problem, due to the interesting and well-known characteristics of SR images, such as the phase contrast effect. The Energy Minimization via Graph Cuts (EMvGC) algorithm represents state-of-art segmentation algorithm, presenting an enormous potential of application in SR-μCT imaging. We describe the application of the algorithm EMvGC with swap move for the segmentation of bone images acquired at the ELETTRA Laboratory (Trieste, Italy).

Corrosion resistance and fatigue strength of stainless steels for chemical tankers: Yajima, H., Sueoka, H., Zama, M., Mori, T. and Kabata, T. Mitsubishi Heavy Ind. Tech. Rev. Oct. 1988 25, (3), 185–190

Synchrotron radiation X-ray micro-computed tomography (SR-μCT) is a robust non-destructive 3D imaging technique that has been widely used to characterize defects in advanced materials and structures, which demonstrates great advantages for defects characterizations and microstructures evolution process investigations of mechanical metamaterials at micro- and nano-scales. In this study, the internal features and damage evolution of the periodic architected mechanical metamaterials manufactured with projection micro litho stereo exposure (PμLSE) are investigated by combining SR-μCT 3D imaging techniques and in-situ compression experiments. The results show that the failure process of periodic architected mechanical metamaterials under compression loading is characterized by the curved surface fracture and curved surface buckling through the damage evolution process. Afterwards, reconstructed geometrical model based on SR-μCT 3D tomography images is proposed to analyze the relationship between the manufactured sample and the mechanical behavior, and the in-situ experiments and numerical simulation results were compared for verification.