scholarly journals In-situ X-ray Differential Micro-tomography for Investigation of Water-weakening in Quasi-brittle Materials Subjected to Four-point Bending

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1405 ◽  
Author(s):  
Petr Koudelka ◽  
Tomas Fila ◽  
Vaclav Rada ◽  
Petr Zlamal ◽  
Jan Sleichrt ◽  
...  
Keyword(s):  
Water Content ◽  
Building Materials ◽  
Brittle Materials ◽  
Vertical Orientation ◽  
X Ray ◽  
Four Point Bending ◽  
Fracture Development ◽  
Micro Tomography ◽  
Water Saturated

Several methods, including X-ray radiography, have been developed for the investigation of the characteristics of water-saturated quasi-brittle materials. Here, the water content is one of the most important factors influencing their strength and fracture properties, in particular, as regards to porous building materials. However, the research concentrated on the three-dimensional fracture propagation characteristics is still significantly limited due to the problems encountered with the instrumentation requirements and the size effect. In this paper, we study the influence of the water content in a natural quasi-brittle material on its mechanical characteristics and fracture development during in-situ four-point bending by employing high-resolution X-ray differential micro-tomography. The cylindrical samples with a chevron notch were loaded using an in-house designed four-point bending loading device with the vertical orientation of the sample. The in-house designed modular micro-CT scanner was used for the visualisation of the specimen’s behaviour during the loading experiments. Several tomographic scans were performed throughout the force-displacement diagrams of the samples. The reconstructed 3D images were processed using an in-house developed differential tomography and digital volume correlation algorithms. The apparent reduction in the ultimate strength was observed due to the moisture content. The crack growth process in the water-saturated specimens was identified to be different in comparison with the dry specimens.

scholarly journals Catastrophic failure: how and when? Insights from 4D in-situ x-ray micro-tomography

2020 ◽  
Author(s):  
Alexis Cartwright-Taylor ◽  
Ian G Main ◽  
Ian B Butler ◽  
Florian Fusseis ◽  
Michael Flynn ◽  
...  
Keyword(s):  
Catastrophic Failure ◽  
X Ray ◽  
Micro Tomography

scholarly journals Isolating the Factors That Govern Fracture Development in Rocks Throughout Dynamic In Situ X‐Ray Tomography Experiments

2019 ◽  
Vol 46 (20) ◽  
pp. 11127-11135 ◽  
Author(s):  
Jessica McBeck ◽  
Neelima Kandula ◽  
John M. Aiken ◽  
Benoît Cordonnier ◽  
François Renard
Keyword(s):  
X Ray ◽  
Fracture Development

scholarly journals Measuring fatigue crack deflections via cracking of constituent particles in AA7050 via in situ x-ray synchrotron-based micro-tomography

2018 ◽  
Vol 116 ◽  
pp. 490-504 ◽  
Author(s):  
Stephen T. Carter ◽  
John Rotella ◽  
Ronald F. Agyei ◽  
Xiaghui Xiao ◽  
Michael D. Sangid
Keyword(s):  
Fatigue Crack ◽  
X Ray ◽  
Micro Tomography

scholarly journals In situ analysis of garnet inclusion in diamond using single-crystal X-ray diffraction and X-ray micro-tomography

2012 ◽  
Vol 24 (4) ◽  
pp. 599-606 ◽  
Author(s):  
Fabrizio Nestola ◽  
Marcello Merli ◽  
Paolo Nimis ◽  
Matteo Parisatto ◽  
Maya Kopylova ◽  
...  
Keyword(s):  
Single Crystal ◽  
In Situ Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Tomography

Ultra Fast In Situ X-Ray Micro-Tomography: Application to Solidification of Aluminium Alloys

2012 ◽  
Vol 706-709 ◽  
pp. 1713-1718 ◽  
Author(s):  
Luc Salvo ◽  
Marco Di Michiel ◽  
Mario Scheel ◽  
Pierre Lhuissier ◽  
B. Mireux ◽  
...  
Keyword(s):  
Solid Phase ◽  
Early Stage ◽  
Copper Alloys ◽  
Cmos Technology ◽  
Acquisition Time ◽  
X Ray ◽  
Research Fields ◽  
Wide Range ◽  
Micro Tomography

X-ray micro-tomography has been applied recently in a wide range of research fields (damage in materials, solidification …). Thanks to the high flux of synchrotrons and specific cameras the total time to acquire a scan was considerably reduced. The use of a specific camera based on CMOS technology allows dividing the acquisition time for a complete scan by a factor of 100. Therefore we have been able to perform in situ solidification of aluminium-copper alloys at high cooling rates (between 1 and 10°C/s) and we will show results concerning the evolution of the microstructure in 3D in the early stage of solidification, in particular the morphology of the solid phase and the kinetics of growth.

scholarly journals Effects of Cr Doping and Water Content on the Crystal Structure Transitions of Ba2In2O5

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1548
Author(s):  
Raphael Finger ◽  
Marc Widenmeyer ◽  
Thomas C. Hansen ◽  
Dirk Wallacher ◽  
Stanislav Savvin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Water Content ◽  
Structural Changes ◽  
Equimolar Amount ◽  
Co2 Conversion ◽  
Temperature Dependent ◽  
X Ray ◽  
Photocatalytic Co2 Conversion ◽  
Cr Doping

Temperature-dependent crystal structure alterations in the brownmillerite-type material Ba2In2O5 play a fundamental role in its applications: i) photocatalytic CO2 conversion; ii) oxygen transport membranes; and iii) proton conduction. This is connected to a reversible uptake of up an equimolar amount of water. In this study, in situ X-ray and neutron diffraction were combined with Raman spectroscopy and solid-state nuclear magnetic resonance experiments to unravel the effects of Cr doping and water content on the crystal structure transitions of Ba2In2O5(H2O)x over a wide temperature range (10 K ≤ T ≤ 1573 K, x < 1). A mixture of isolated and correlated protons was identified, leading to a highly dynamic situation for the protons. Hence, localisation of the protons by diffraction techniques was not possible. Cr doping led to an overall higher degree of disorder and stabilisation of the tetragonal polymorph, even at 10 K. In contrast, a further disordering at high temperatures, leading to a cubic polymorph, was found at 1123 K. Cr doping in Ba2In2O5 resulted in severe structural changes and provides a powerful way to adjust its physical properties to the respective application.

scholarly journals INSTRUMENTATION OF FOUR-POINT BENDING TEST DURING 4D COMPUTED TOMOGRAPHY

2018 ◽  
Vol 18 ◽  
pp. 20 ◽  
Author(s):  
Daniel Kytýř ◽  
Tomáš Fíla ◽  
Petr Koudelka ◽  
Ivana Kumpová ◽  
Michal Vopálenský ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Process Zone ◽  
Brittle Materials ◽  
Time Lapse ◽  
Bending Test ◽  
Ct Scanner ◽  
X Ray ◽  
Four Point Bending ◽  
4D Computed Tomography

High-resolution time-lapse micro-focus X-ray computed tomography is an effective method for investigation of deformation processes on volumetric basis including fracture propagation characteristics of non-homogeneous materials subjected to mechanical loading. This experimental method requires implementation of specifically designed loading devices to X-ray imaging setups. In case of bending tests, our background research showed that no commercial solution allowing for reliable investigation of so called fracture process zone in quasi-brittle materials is currently available. Thus, this paper is focused on description of recently developed in-situ four-point bending loading device and its instrumentation for testing of quasi-brittle materials. Proof of concept together with the pilot experiments were successfully performed in a CT scanner TORATOM. Based on results of the pilot experiments, we demonstrate that crack development and propagation in a quasi-brittle material can be successfully observed in 3D using high resolution 4D micro-CT under loading.

Automating Structural Modeling of Composites Enriched by X-Ray Micro-Tomography and Digital Imaging Data

2018 ◽  
Author(s):  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos ◽  
John C. Steuben ◽  
Andrew J. Birnbaum ◽  
Jim Lua ◽  
...  
Keyword(s):  
Digital Imaging ◽  
Composite Structures ◽  
Structural Modeling ◽  
Fiber Reinforced Polymers ◽  
Imaging Data ◽  
Element Analysis ◽  
X Ray ◽  
Four Point Bending ◽  
Recent Developments ◽  
Micro Tomography

The manufacturing processes of Fiber Reinforced Polymers (FRPs) as composite materials are frequently prone to the creation of various types of undesired morphologies and defects. These can include layer waviness, inclusions, and voids. Structural modeling for Finite Element Analysis (FEA) of structures including such morphologies and defects has not been practically realizable until recent developments in X-ray microtomography enabled the detection of such defects in a nondestructive manner. In the present work we present our initial steps toward the FEA modeling of FRP composite structures that leverage utilization of X-ray and regular digital imaging data as well as semi-automated methods for generating appropriate FEA models. Emphasis is given in defining waviness-driven curvilinear coordinate systems, defect identification and integration of both waviness and defects to FEA analysis including a planestrain application of a curved composite bracket under four-point bending conditions.

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