Tomography of Materials and Structures最新文献

{"title":"Influence of X-Ray beam exposure on the development of gas bubbles during triaxial testing of sand using 3D synchrotron micro-computed tomography","authors":"Mohammed Elnur ,&nbsp;Khalid A. Alshibli","doi":"10.1016/j.tmater.2023.100016","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100016","url":null,"abstract":"<div><p>The constitutive behavior of granular materials is highly influenced by the degree of saturation and whether a saturated or unsaturated framework is adopted to model the behavior of granular materials. Conventional axisymmetric triaxial compression (CTC) testing of saturated specimens tends to assume that the specimen remains saturated during shearing. X-ray computed tomography (CT) has allowed for 3D in-situ measurements beyond the global scale to investigate microscale and localized events such as fabric evolution. The literature reported several CT-coupled geotechnical experiments of saturated specimens; however, no study examined how X-ray exposure might affect the specimen, specifically the radiolysis of pore water. In this study, we present the synchrotron micro-computed tomography (SMT) results of experiments performed on sand specimens without shearing (acrylic tubes) and with shearing (CTC experiments) to assess the influence of X-ray exposure on the development of the gas phase of saturated sand. The observed phase changes were dependent on the initial pore water pressure and duration of exposure to the X-ray; the behavior of individual gas bubbles was dependent on the bubble’s surrounding sand grains and pore throat sizes leading to changes in the degree of saturation.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"3 ","pages":"Article 100016"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49730310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of self-piercing rivet joints using X-ray computed tomography","authors":"Papangkorn Jessadatavornwong ,&nbsp;Garret Huff ,&nbsp;Amanda Freis ,&nbsp;Raj Das ,&nbsp;Adrian P. Mouritz ,&nbsp;Mark A. Easton","doi":"10.1016/j.tmater.2023.100010","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100010","url":null,"abstract":"<div><p>Self-piercing rivet (SPR) joining is a process that has been adopted in the automotive industry, and it is important to be able to characterize SPR joints non-destructively. X-ray computed tomography (CT) allows visualizing the internal structure of the sample whilst preserving the workpiece. In this work, the application of X-ray CT to SPR joint characterization is investigated. Many features of a riveted joint can be observed. This includes the boundary between sheet interfaces and the positions where the substrates and rivet meet, which are important to quality assessment. In the case of similar materials, some of these features become difficult to observe but the presence of adhesive between the sheets enables the features to be more easily observed. Furthermore, substrate fracture and rivet cracks, radial cracks and the asymmetry of SPR joints can be detected due to the difference in greyscale to the surrounding materials. It is also revealed that image resolution plays an important role in defect detectability of the X-ray CT technique.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100010"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49718502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seeing the whole picture: Methods for getting the most from micro X-ray computed tomography of TRISO nuclear fuel particles","authors":"William C. Chuirazzi ,&nbsp;Joshua J. Kane ,&nbsp;Nikolaus L. Cordes ,&nbsp;John D. Stempien ,&nbsp;Rahul R. Kancharla ,&nbsp;Fei Xu","doi":"10.1016/j.tmater.2023.100005","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100005","url":null,"abstract":"<div><p>Tristructural isotropic (TRISO) coated fuel particles are a nuclear fuel form under extensive study for use in advanced nuclear reactor concepts. TRISO fuels are subjected to high temperature neutron irradiations and then examined to assess their performance by determining fission product retention and studying morphological changes. Micro X-ray computed tomography is one method of nondestructively studying the effects of TRISO performance. This work addresses the need for image processing to remove X-ray tomographic reconstruction artifacts that prevent the study of TRISO features, as the TRISO particles’ high Z kernel can introduce metal artifacts that degrade the image quality in the surrounding low Z coating layers. These metal artifacts were reduced by imaging the TRISO particles with both high- and low-energy X-rays and applying a mask to the radiographs obtained with low-energy X-rays to digitally remove the dense fuel kernel region. These masked radiographs were then used to produce a tomographic reconstruction which was combined with the tomographic reconstruction of the high-energy data. This enabled the relatively-low-density TRISO buffer layer to be examined in more detail, providing information on irradiation induced dimensional changes of the coatings. This methodology, which helps see the full picture of a TRISO particle, is not limited to nuclear fuels but can be applied to systems that contain highly attenuating material surrounded by less dense materials.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100005"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-scan refinement technique combining cone-beam tomography and laminography","authors":"Olaf Delgado-Friedrichs ,&nbsp;Andrew M. Kingston ,&nbsp;Benjamin Young ,&nbsp;Shane J. Latham ,&nbsp;Glenn R. Myers ,&nbsp;Adrian P. Sheppard","doi":"10.1016/j.tmater.2023.100012","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100012","url":null,"abstract":"<div><p>In a fine-focus geometry, for a given detector, the resolution achievable by conventional tomographic region-of-interest (ROI) imaging is limited by the smallest possible distance of the radiation source from the rotation axis, i.e., the radius of the smallest cylinder about the rotation axis that encloses the object. In situations where the specimen to be imaged is irregularly shaped, or the ROI is off-centre, higher magnification can only be achieved from a limited range of angles, (possibly in a separate scan), and a tomographic reconstruction technique able to incorporate this additional data would be advantageous. Here we present such a technique for imaging planar (or laminar) objects based on a combination of multiple tomography and laminography scans with increasing magnification that employ helical and planar source trajectories respectively. Relative to laminography, this hierarchical combination improves depth resolution, (longitudinal direction), as well as reducing imaging artefacts. Relative to full-field tomography the proposed method increases resolution, particularly in the plane of the specimen, (transverse direction). The foundation of the technique is a generalisation of accelerated multi-grid tomographic reconstruction methods to the case of multiple independent collections of radiographs. Here we first demonstrate the concepts and performance of this technique through a simulated example. We then demonstrate the successful application of the method experimentally to a thin rock section and a printed circuit board.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100012"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49718505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A thresholding based iterative reconstruction method for limited-angle tomography data","authors":"P. Piault ,&nbsp;A. King ,&nbsp;L. Henry ,&nbsp;J.S. Rathore ,&nbsp;N. Guignot ,&nbsp;J.-P. Deslandes ,&nbsp;J.-P. Itié","doi":"10.1016/j.tmater.2023.100008","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100008","url":null,"abstract":"<div><p>Limited-angle computed tomography is often imposed by in-situ experiments combining tomography with sample environments. The missing projection data causes artifacts in the tomographic reconstruction. We demonstrate that the correction of these numerical artifacts can be achieved by restoring the missing projections using an iterative reconstruction scheme. The reconstruction is regularized using segmentation, and thresholds determined from the histogram of reconstructed gray levels. The missing projections are simulated by forward projection and incorporated into the original measured dataset to give a complete angular span. This scheme typically converges within a few iterations. Results are presented for several measurements using parallel-beam synchrotron X-ray tomography and 165 degrees of valid projection data. A simple numerical simulation is used to verify the validity of the experimental results.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100008"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49708800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward accurate prediction of partial-penetration laser weld performance informed by three-dimensional characterization – Part I: High fidelity interrogation","authors":"Andrew T. Polonsky ,&nbsp;Jonathan D. Madison ,&nbsp;Mary Arnhart ,&nbsp;Helena Jin ,&nbsp;Kyle N. Karlson ,&nbsp;Alyssa J. Skulborstad ,&nbsp;James W. Foulk ,&nbsp;Scott G. Murawski","doi":"10.1016/j.tmater.2023.100006","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100006","url":null,"abstract":"<div><p>The mechanical response of laser welds in complex load states can be highly variable, underlying the need for models that can accurately predict mechanical behavior to ensure component performance. In Part I of this work, a series of partial penetration welds of 304L stainless steel have been characterized in three dimensions using micro-computed tomography (μCT). The effect of segmentation approaches for handling raw three-dimensional data has been studied in detail. Such characterization enables for comprehensive analysis of the physical distribution and shape of porosity within the weld as well as details on the geometry of the joint, which are used in conjunction with mechanical testing to understand the impact of these factors on weld performance. Joint geometry, in particular the prescribed gap between the plates, has a large impact on the tensile response of weldments, which can be understood to primarily depend on the local load state that develops around the joint. Using high-fidelity three-dimensional data, the mechanical response of individual weldments, including the peak load and displacement to failure, can be accurately predicted using finite element simulations. The details of the modelling approach, and its sensitivity to various idealizations, are the focus of Part II of this work.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100006"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49709019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Noise and blur removal from corrupted X-ray computed tomography scans: A multilevel and multiscale deep convolutional framework approach with synthetic training data (BAM SynthCOND)","authors":"Athanasios Tsamos ,&nbsp;Sergei Evsevleev ,&nbsp;Giovanni Bruno","doi":"10.1016/j.tmater.2023.100011","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100011","url":null,"abstract":"<div><p>Regardless of the experimental care practiced in acquiring X-ray computed tomography (XCT) data, artifacts might still exist, such as noise and blur. This is typical for fast XCT data acquisitions (e.g., in-situ investigations), or low-dose XCT. Such artifacts can complicate subsequent analysis of the data. Digital filters can moderately cure extensive artifacts. The selection of filter type, intensity, and order of application is not always straightforward. To tackle these problems, a complete sequential multilevel, multi-scale framework: BAM SynthCOND, employing newly designed deep convolutional neural networks (DCNNs), was formulated. Although data conditioning with neural networks is not uncommon, the main complication is that completely artifact-free XCT data for training do not exist. Thus, training data were acquired from an in-house developed library (BAM SynthMAT) capable of generating synthetic XCT material microstructures. Some novel DCNN architectures were introduced (2D/3D ACEnet_Denoise, 2D/3D ACEnet_Deblur) along with the concept of Assertive Contrast Enhancement (ACE) training, which boosts the performance of neural networks trained with continuous loss functions. The proposed methodology accomplished very good generalization from low resemblance synthetic training data. Indeed, denoising, sharpening (deblurring), and even ring artifact removal performance were achieved on experimental post-CT scans of challenging multiphase Al-Si Metal Matrix Composite (MMC) microstructures. The conditioning efficiencies were: 92% for combined denoising/sharpening, 99% for standalone denoising, and 95% for standalone sharpening. The results proved to be independent of the artifact intensity. We believe that the novel concepts and methodology developed in this work can be directly applied on the CT projections prior to reconstruction, or easily be extended to other imaging techniques such as: Microscopy, Neutron Tomography, Ultrasonics, etc.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100011"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49732453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional imaging of microstructural evolution in SEM-based nano-CT","authors":"Jonas Fell ,&nbsp;Christoph Pauly ,&nbsp;Michael Maisl ,&nbsp;Simon Zabler ,&nbsp;Frank Mücklich ,&nbsp;Hans-Georg Herrmann","doi":"10.1016/j.tmater.2023.100009","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100009","url":null,"abstract":"<div><p>Scanning electron microscopy (SEM) is a powerful and versatile technique for materials characterization and present in many laboratories. The integration of an X-ray target holder and detector allows expanding the modalities of SEM by X-ray imaging. These little hardware adaptations enable radiography or X-ray computed tomography (CT) to gain three-dimensional (3D) information about a sample to be investigated. Since SEM-based CT is a non-destructive technique, the method can also image time-dependent changes in microstructure. Presented is the ability of SEM-based nano-CT to image the microstructural evolution of an aluminum-germanium (AlGe32) alloy as a result of annealing. First, the non-destructive CT method is used for an overview scan to identify a hidden region of interest (ROI) in the sample volume at low resolution. The following FIB target preparation reveals the microstructure, which is stepwise annealed and investigated with SEM-based nano-CT at high resolution afterwards. The resulting reconstructed volumes gained from the laboratory-based system are visualized in 3D and show the morphology changes of microstructure. Quantitative analysis reveals grain coarsening and the formation of precipitations in the size of 300–1000 nm. These time-dependent processes are additionally correlated with hardness measurements of the Al alloy.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100009"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49708941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward accurate prediction of partial-penetration laser weld performance informed by three-dimensional characterization – Part II: μCT based finite element simulations","authors":"Kyle N. Karlson ,&nbsp;Alyssa J. Skulborstad ,&nbsp;Jonathan D. Madison ,&nbsp;Andrew T. Polonsky ,&nbsp;Helena Jin ,&nbsp;Amanda Jones ,&nbsp;Brett Sanborn ,&nbsp;Sharlotte L.B. Kramer ,&nbsp;Bonnie R. Antoun ,&nbsp;Wei-Yang Lu","doi":"10.1016/j.tmater.2023.100007","DOIUrl":"https://doi.org/10.1016/j.tmater.2023.100007","url":null,"abstract":"<div><p>The mechanical behavior of partial-penetration laser welds exhibits significant variability in engineering quantities such as strength and apparent ductility. Understanding the root cause of this variability is important when using such welds in engineering designs. In Part II of this work, we develop finite element simulations with geometry derived from micro-computed tomography (<em>μ</em>CT) scans of partial-penetration 304L stainless steel laser welds that were analyzed in Part I. We use these models to study the effects of the welds’ small-scale geometry, including porosity and weld depth variability, on the structural performance metrics of weld ductility and strength under quasi-static tensile loading. We show that this small-scale geometry is the primary cause of the observed variability for these mechanical response quantities. Additionally, we explore the sensitivity of model results to the conversion of the <em>μ</em>CT data to discretized model geometry using different segmentation algorithms, and to the effect of small-scale geometry simplifications for pore shape and weld root texture. The modeling approach outlined and results of this work may be applicable to other material systems with small-scale geometric features and defects, such as additively manufactured materials.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"2 ","pages":"Article 100007"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49708946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kitchen-based light tomography - a DIY toolkit for advancing tomography - by and for the tomography community","authors":"Emanuel Larsson ,&nbsp;Doğa Gürsoy ,&nbsp;Stephen A. Hall","doi":"10.1016/j.tmater.2022.100001","DOIUrl":"https://doi.org/10.1016/j.tmater.2022.100001","url":null,"abstract":"<div><p>We present a recipe for building a portable DIY toolkit, entitled Kitchen-Based Light Tomography (KBLT) for performing tomography using visible light with low-cost and easily accessible components. We also present different use cases to mimic different challenges in tomography, such as imaging time evolving samples. All the software for motor controls, image acquisition, image reconstruction and analysis is open-sourced and available online. The fast acquisition of KBLT datasets permits 4D scanning (3D plus time), also in combination with so-called sample environments, which can support the advancement of improved image reconstruction algorithms. We believe this ‘<em>Do it yourself</em>’ (DIY) toolkit will be useful to tomography users, beamline scientists and computational researchers, and the tomography community in general.</p></div>","PeriodicalId":101254,"journal":{"name":"Tomography of Materials and Structures","volume":"1 ","pages":"Article 100001"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49718493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}