Article
Materials Science, Multidisciplinary
A. Dorronsoro, J. Navarrete, A. Pan, E. Castano, J. M. Sanchez, J. Alkorta
Summary: A new method based on focused ion beam (FIB) slit machining and digital image correlation algorithm has been developed to measure residual stresses at the surface of hardmetal components. The method provides higher spatial resolution compared to standard X-ray diffraction methods. Successful application on as-ground and femto-laser textured surfaces shows good correlation with the standard sin2 psi XRD technique. The research concludes that femtosecond laser texturing does not induce perfectly adiabatic changes, as residual stresses are reduced by 15%.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
N. M. Dang, W. -Y. Ku, Z. -Y. Wang, C. -H. Lin, T. Y. -F. Chen, M. -T. Lin
Summary: This study developed a method for measuring residual stress in bilayer thin films and proved its practicality and applicability through comparison with other studies.
EXPERIMENTAL MECHANICS
(2022)
Article
Chemistry, Physical
Dibakor Boruah, Nele Dewagtere, Bilal Ahmad, Rafael Nunes, Jeroen Tacq, Xiang Zhang, Hua Guo, Wim Verlinde, Wim De Waele
Summary: This study demonstrates the capability of the DIC technique in evaluating full-field residual stresses in WAAM components. The bending deformation during unclamping of WAAM parts was monitored using DIC, and the residual stresses were calculated from the captured strain field. The results were verified with an analytical model and validated using established residual stress measurement techniques.
Article
Engineering, Electrical & Electronic
Shengxiao Jin, Ling Xia, Yifei Mao, Xiaoyu Chen, Zhuojie Chen, Can Li, Wengang Wu, Jun Xu
Summary: Focused ion beam (FIB) with keV Ga+ can introduce nanoscale localized tensile stress in various materials, which is utilized to assemble 2D nano-film patterns into 3D structures. A strained-bilayer-system model is proposed to describe the bending angle of the patterns. By applying proper stress-introducing strategy, a 3D cubic frame and helices are fabricated using FIB stress induced deformation (FIB-SID) technology. A programmable quasi-parallel FIB fabrication method is developed for efficient and consistent fabrication of 3D nanostructures.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Multidisciplinary Sciences
Akio Yoneyama, Kotaro Ishiji, Atsushi Sakaki, Yutaka Kobayashi, Masayuki Inaba, Kazunori Fukuda, Kumiko Konishi, Akio Shima, Daiko Takamatsu
Summary: X-ray topography is a powerful method for analyzing crystal defects and strain in crystalline materials non-destructively. However, conventional X-ray topography lacks depth information on defects and dislocations. In this study, we developed a novel three-dimensional micro-X-ray topography technique (3D mu-XRT) that combines Bragg-case section topography with focused sheet-shaped X-rays, enabling non-destructive observation of internal defects and dislocations with a depth accuracy on the order of 1 µm. The visualization of various defects in SiC power device chips demonstrated the potential of 3D mu-XRT for highly sensitive and non-destructive analysis of material crystallinity.
SCIENTIFIC REPORTS
(2023)
Article
Materials Science, Composites
Mahoor Mehdikhani, Christian Breite, Yentl Swolfs, Jeroen Soete, Martine Wevers, Stepan V. Lomov, Larissa Gorbatikh
Summary: This study explores the potential of Digital Volume Correlation (DVC) in detecting and characterizing damage in fiber-reinforced composites using in-situ X-ray Computed Tomography. Through preliminary analysis of digital deformation images and real-deformation images acquired during in-situ tensile loading, DVC proves to be a promising tool for quantification of deformation and damage at both mesoscale and microscale levels. Damage mechanisms in fiber-reinforced composites are successfully detected and characterized using DVC, showing the limitations of traditional methods like grayscale thresholding.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Optics
Stefan Berg-Johansen, Martin Neugebauer, Andrea Aiello, Gerd Leuchs, Peter Banzer, Christoph Marquardt
Summary: Vector beams have been shown to be utilized for fast kinematic sensing through measurements of their global polarization state. The method relies on correlations between the spatial and polarization degrees of freedom of the illuminating field, and has been extended to the nonparaxial regime, demonstrating position sensing of Mie particles in three dimensions. This work highlights the potential of polarization analysis in optical tweezers employing structured light.
Article
Materials Science, Multidisciplinary
Aurelio Borzi, Robert Zboray, Simone Dolabella, Sebastien Brun, Florian Telmont, Peter Kupferschmied, Jean-Francois Le Neal, Pedrag Drljaca, Gianni Fiorucci, Alex Dommann, Antonia Neels
Summary: Advanced methods such as high-resolution X-ray diffraction and X-ray micro CT enable precise determination of materials' residual stress, volume, and lattice defects, providing powerful tools for industrial microfabrication. This study investigates key parameters related to a novel wafer-bonding process, Impulse Current Bonding (ICB), and compares it to standard anodic bonding for MEMS production. The results show that ICB does not induce relevant residual stress or defects at the interface, reduces thermal budget by 85% compared to anodic bonding, and has potential for various applications including biocompatible devices for bio-implants.
APPLIED MATERIALS TODAY
(2022)
Article
Materials Science, Coatings & Films
O. P. Oladijo, L. L. Collieus, B. A. Obadele, E. T. Akinlabi
Summary: The study aimed to investigate the effect of residual stresses on the tribological behavior of high velocity oxy-fuel sprayed Inconel 625 coatings. Results showed a positive correlation between the residual stress state of the coatings and their wear volumes.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Tsung-Pin Hung, Hsiu-An Tsai, Ah-Der Lin
Summary: This study investigated the surface residual stress of AISI 1045 steel after quenching with a YAG laser. Both experimental and numerical analyses were conducted to study the effect of laser quenching on the surface stress. The results showed that laser quenching induced compressive stresses on the surface of the steel.
Article
Chemistry, Physical
Simi Debnath, Ratan Das
Summary: PVP capped nickel ferrite nanocrystals (NFN) and cobalt doped nickel ferrite nanocrystals (CNFN) were successfully prepared using thermal heat treatment method, followed by sintering at 700 degrees C. The synthesized nanocrystals were analyzed through XRD, TEM and SEM to study their structural, morphological and magnetic properties. The study showed increase in saturation magnetization and coercivity values with Co doping in NFN, indicating potential applications in memory devices, magnetic recording media and adsorption of toxic materials in water.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Multidisciplinary
Mehdi Mokhtarishirazabad, Martin McMillan, V. D. Vijayanand, Chris Simpson, Dylan Agius, Christopher Truman, David Knowles, Mahmoud Mostafavi
Summary: Electron beam welding is an advanced technique that minimizes heat affected zone and weld-induced distortion, reducing residual stresses in safety-critical components. This study utilizes a crystal plasticity finite element framework to determine the mechanical properties of weld material based on its microstructure. By comparing the results with X-ray diffraction data, the accuracy of the simulated residual strain is validated.
INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING
(2023)
Article
Radiology, Nuclear Medicine & Medical Imaging
Linxi Shi, N. Robert Bennett, Eric Nguyen, Carolyn MacDonald, Adam Wang, Wu Liu
Summary: This study demonstrated that the focused kV x-ray technique can substantially improve the imaging resolution for small animal imaging.
Article
Engineering, Mechanical
Pavol Dlhy, Jan Poduska, Pavel Pokorny, Michal Jambor, Lubos Nahlik, Daniel Kajanek, Rostislav Fajkos, Pavel Hutar
Summary: The manufacturing process of railway axles often involves inducing compressive residual stress on the surface to enhance impact resistance and fatigue lifetime. Existing methods for determining residual stress are limited to surface or near-surface measurements. This study aims to develop a reliable methodology for measuring residual stress in the entire cross-section of a railway axle. Two methods combining destructive techniques, X-ray diffraction, and numerical simulations were applied to an induction-hardened axle. The results were compared to validate their accuracy.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Audiology & Speech-Language Pathology
Pieter Livens, Pieter G. G. Muyshondt, Joris J. J. Dirckx
Summary: Prestrain in the tympanic membrane (TM) of cadaveric rabbit ears was measured using stereo digital image correlation, with incisions made to release the prestrain. Average prestrain values around the incisions ranged from 3.52% to 13.62%, showing no clear differences between radial and circular incisions.
Article
Chemistry, Multidisciplinary
Yuliya Kan, Julia Bondareva, Eugene S. Statnik, Julijana Cvjetinovic, Svetlana Lipovskikh, Arkady S. Abdurashitov, Maria A. Kirsanova, Gleb B. Sukhorukhov, Stanislav A. Evlashin, Alexey Salimon, Alexander M. Korsunsky
Summary: This study focuses on the fabrication of core-shell nanofiber mats using electrospinning technique. The core-shell structure was modified with silica nanoparticles and graphene oxide to enhance fiber integrity and stability. The influence of nano additives and crosslinking conditions on fiber diameter, hydrolysis, and mechanical properties were investigated. The results suggest that electrospun core-shell nanofiber mats have great potential for biomedical applications.
Article
Materials Science, Multidisciplinary
Leon Romano Brandt, Kazunori Nishio, Enrico Salvati, Kevin P. Simon, Chrysanthi Papadaki, Taro Hitosugi, Alexander M. Korsunsky
Summary: The novel solid state, thin film Li-NMC batteries achieved high charge and discharge rates, reduced interface resistance, and improved capacity retention by optimizing cathode grain orientation and residual stress state.
APPLIED MATERIALS TODAY
(2022)
Article
Materials Science, Multidisciplinary
Enrico Salvati, Alessandro Tognan, Luca Laurenti, Marco Pelegatti, Francesco De Bona
Summary: The study explores a method to predict the fatigue finite life of defective materials using machine learning and a Physics-Informed Neural Network framework, overcoming the issue of being unable to consider the actual morphology of defects. By introducing novel Fracture Mechanics constraints, the training process of the Neural Network is enhanced, requiring a smaller experimental dataset.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Sophie A. M. McNair, Jiraphant Srisuriyachot, Samuel Omole, Thomas Connolley, Andrew Rhead, Alexander J. G. Lunt
Summary: Small-diameter, thin-walled pipes are widely used in industries such as high-energy physics, heat transfer, nuclear, medical, and communications. The performance of thin-walled pipe welds less than 0.5 mm in width is difficult to determine due to the lack of existing standards. Porosity is a determining factor in the performance of the connection. This study found that reducing residual stresses is more important than reducing porosity for improving weld strength.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Manufacturing
Yuanbo T. Tang, Chinnapat Panwisawas, Benjamin M. Jenkins, Junliang Liu, Zhao Shen, Enrico Salvati, Yilun Gong, Joseph N. Ghoussoub, Stefan Michalik, Bryan Roebuck, Paul A. J. Bagot, Sergio Lozano-Perez, Chris R. M. Grovenor, Michael P. Moody, Alexander M. Korsunsky, David M. Collins, Roger C. Reed
Summary: A supersaturated y phase microstructure is produced in Ni-based superalloys using laser powder bed fusion (L-PBF) technology. The cooling rate from the process suppresses the solid-state precipitation of the y ’ phase. This study investigates the behavior of the material during heat treatment and sheds light on the manipulation of the y ’ precipitate distribution for tailoring microstructure in additively manufactured superalloys.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Mechanical
Marco Pelegatti, Denis Benasciutti, Francesco De Bona, Alex Lanzutti, Jelena Srnec Novak, Enrico Salvati
Summary: This study investigated the low cycle fatigue (LCF) behavior of 316L steel, which is widely used in sectors requiring reliable durability analysis. The cyclic elastoplastic behavior of the material was accurately described using the Chaboche-Voce combined plasticity model. The fatigue life was modeled using the Manson-Coffin curve and simplified models derived from static properties of the material, some of which showed remarkable accuracy. A quantitative comparison with wrought-processed 316L steel revealed different cyclic elastoplastic responses but comparable fatigue strengths.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Benedict A. Rogers, Max D. A. Valentine, Alexander J. G. Lunt, Elise C. Pegg, Vimal Dhokia
Summary: Novel polygon celled 3D star structures were developed to reduce anisotropy in metamaterials. A new lattice design ontology and low cost optimization method were used, resulting in reduced anisotropy and successful manufacturing. This study provides a practical way for strain based design and contributes to the growth of metamaterials.
MATERIALS & DESIGN
(2023)
Article
Engineering, Civil
Pawel Czapski, Alexander J. G. Lunt
Summary: The aim of this study was to investigate the influence of manufacturing on the buckling and post-buckling behavior of thin-walled, CFRP columns. Static compression tests were performed on channel-section profiles made of an eight-layered symmetric laminate, manufactured by two distinct methods. The results showed that the second method was more material efficient and provided higher buckling resistance. Finite element models were also compared, showing that residual stresses significantly influenced the buckling response of the square cross section samples. These findings have important implications for the design and production of CFRP channels with enhanced buckling performance.
THIN-WALLED STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Stefano Bacchetti, Michele A. Coppola, Francesco De Bona, Alex Lanzutti, Pierpaolo Miotti, Enrico Salvati, Francesco Sordetti
Summary: In this study, a combined numerical and experimental approach was used to investigate the hot metal extrusion process of Inconel 718 alloy. It was found that higher initial temperature of the billet resulted in lower extrusion force required, but a trade-off must be sought to avoid excessive temperature and surface crack formation. The extrusion speed also played a relevant role, with an optimal value needed to minimize surface crack formation and the melting of intergranular niobium carbides.
Article
Chemistry, Physical
Pawel Czapski, Jiraphant Srisuriyachot, Filip Kazmierczyk, Tomasz Was, Patryk Jakubczak, Igor P. Dolbnya, Jaroslaw Bienias, Alexander J. G. Lunt
Summary: This study analyzed carbon fiber composite columns produced via different methods using synchrotron X-ray diffraction and radiography. The results showed that the production methods had an impact on lattice strain and fiber orientation, and could reduce buckling load. These findings are of great significance for optimizing structural design, production, and loading capability.
Article
Engineering, Multidisciplinary
Jiraphant Srisuriyachot, Jean Benezech, Guillaume Couegnat, Sophie A. M. McNair, Thomas Maierhofer, Richard Butler, Alexander J. G. Lunt
Summary: This paper presents the first study on in-situ pure compressive kink-band failure in Uni-Directional Carbon Fibre-Reinforced Polymer composites (UD-CFRPs) with a notch using synchrotron micro-Computed Tomography (micro-CT). The study compares the failure behavior of baseline samples with defect-rich samples containing micro-defects such as voids and fiber misalignment. The results reveal changes in fiber orientation and localized strain, and show that the defect-rich samples form narrower conjugate kink bands inclined at 45 degrees.
COMPOSITES PART B-ENGINEERING
(2023)
Article
Mechanics
Emanuele Avoledo, Alessandro Tognan, Enrico Salvati
Summary: Substantial advances in fatigue estimation of defective materials can be achieved through the use of Physics-Informed Neural Network (PINN), which can account for multiple defect descriptors while maintaining accurate predictions. This study aims to assess the variability of PINN-estimated fatigue life due to input uncertainties and explore the influence of defect descriptors in fatigue life using sensitivity indices. The findings suggest that traditionally neglected defect descriptors may have a relevant role in specific circumstances.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
Alessandro Tognan, Enrico Salvati
Summary: Probabilistic defect-tolerant fatigue design protocols are widely used in structural engineering. El Haddad's (EH) curves are employed for the evaluation of fatigue endurance limit, calibrated using Logistic Regression (LR) and Maximum a Posteriori (MAP) based on data from fatigue characterization and fractography. Prior information is introduced for commonly used metallic alloys based on extensive literature research. EH curves are retrieved through Monte Carlo simulation to support probabilistic engineering practice.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Engineering, Mechanical
Simone Dreon, Lorenzo Scalera, Enrico Salvati
Summary: Rigorous protocols must be followed to avoid structural damage and failures when mounting ball bearings. For angular ball bearings, axial forces should be applied over the raceway subjected to the shrink-fit. Analytical methods can replace FEM-based tools for evaluating bearing mounting force and contact pressure, although FEM modelling may be more accurate for generic boundary conditions and intricate geometrical features.
INTERNATIONAL JOURNAL OF MECHANICS AND MATERIALS IN DESIGN
(2023)
Article
Engineering, Multidisciplinary
Alessandro Tognan, Andrea Patane, Luca Laurenti, Enrico Salvati
Summary: This study demonstrates how advanced Bayesian Physics-guided Neural Network (B-PGNN) approaches can be used to probabilistically predict fatigue failures in materials with defects. By developing a B-PGNN to predict the fatigue failure probability of samples containing defects, this method offers an advanced practical approach to support probabilistic design against fatigue failure.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)