Imperial College London
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ProfessorCatherineO'Sullivan

Faculty of Engineering, Department of Civil and Environmental Engineering

Professor of Particulate Soil Mechanics
 
 
 
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Contact

 

+44 (0)20 7594 6117cath.osullivan Website

 
 
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Location

 

501Skempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Su:2022:www.scientific.net/ssp.327.127,
author = {Su, TC and O'Sullivan, C and Yasuda, H and Gourlay, CM},
doi = {www.scientific.net/ssp.327.127},
journal = {Solid State Phenomena},
pages = {127--132},
title = {Understanding the rheological transitions in semi-solid alloys by a combined <i>In Situ</i> Imaging and granular micromechanics modeling approach},
url = {http://dx.doi.org/10.4028/www.scientific.net/ssp.327.127},
volume = {327},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - To gain better understanding of rheological transitions from suspension flow to granular deformation and shear cracking, this research conducted shear-deformation on globular semi-solid Al-Cu alloys to study the rheological behavior of semi-solid as a function of solid fraction (38% - 85%) and shear rate (10<jats:sup>-4</jats:sup> – 10<jats:sup>-1</jats:sup> s<jats:sup>-1</jats:sup>) under real-time synchrotron radiography observation. By analyzing 17 X-ray imaging datasets, we define three rheological transitions: (i) the critical solid fraction from a suspension to a loosely percolating assembly; (ii) from the net contraction of a loose assembly to the net dilation of a densely packed assembly, and (iii) to shear cracking at high solid fraction and shear rate. Inspired by in-situ observations of semi-solid deformation showing a disordered assembly of percolating crystals in partially-cohesive contact with liquid flow, we reproduced a two-phase sample using the coupled lattice Boltzmann method-discrete element method (LBM-DEM) simulation approach for granular micromechanical modeling. In DEM, each globular Al grain is represented by a discrete element, and the flow of interstitial liquid is solved by LBM. The LBM-DEM simulations show quantitative agreement of semi-solid strain localization with the experiments and are used to explore the components involved in the shear rate dependence of the transitions, and the role of liquid pressure on the initiation of shear cracking.
AU  - Su,TC
AU  - O'Sullivan,C
AU  - Yasuda,H
AU  - Gourlay,CM
DO  - www.scientific.net/ssp.327.127
EP  - 132
PY  - 2022///
SN  - 1012-0394
SP  - 127
TI  - Understanding the rheological transitions in semi-solid alloys by a combined <i>In Situ</i> Imaging and granular micromechanics modeling approach
T2  - Solid State Phenomena
UR  - http://dx.doi.org/10.4028/www.scientific.net/ssp.327.127
UR  - https://www.scientific.net/SSP.327.127
VL  - 327
ER  -
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