scholarly journals Ultra-high-speed x-ray imaging of shock-induced cavity collapse in a solid medium

2020 ◽  
Author(s):  
Emilio M. Escauriza ◽  
Joao P. Duarte ◽  
David J. Chapman ◽  
Lukasz Farbaniec ◽  
John C. Jonsson ◽  
...  
Keyword(s):  
High Speed ◽  
Solid Medium ◽  
X Ray ◽  
Cavity Collapse ◽  
Ultra High Speed ◽  
X Ray Imaging

scholarly journals High-speed X-ray imaging of a ball impacting on loose sand

2015 ◽  
Vol 777 ◽  
pp. 690-706 ◽  
Author(s):  
Tess Homan ◽  
Rob Mudde ◽  
Detlef Lohse ◽  
Devaraj van der Meer
Keyword(s):  
High Speed ◽  
Packing Fraction ◽  
Loose Sand ◽  
X Ray ◽  
Air Bubble ◽  
Cavity Collapse ◽  
X Ray Imaging ◽  
Custom Made ◽  
Set Up ◽  
Entrapped Air

When a ball is dropped in fine very loose sand, a splash and subsequently a jet are observed above the bed, followed by a granular eruption. To directly and quantitatively determine what happens inside the sand bed, high-speed X-ray tomography measurements are carried out in a custom-made set-up that allows for imaging of a large sand bed at atmospheric pressures. Herewith, we show that the jet originates from the pinch-off point created by the collapse of the air cavity formed behind the penetrating ball. Subsequently, we measure how the entrapped air bubble rises through the sand, and show that this is consistent with bubbles rising in continuously fluidized beds. Finally, we measure the packing fraction variation throughout the bed. From this we show that there is (i) a compressed area of sand in front of and next to the ball while the ball is moving down, (ii) a strongly compacted region at the pinch-off height after the cavity collapse and (iii) a relatively loosely packed centre in the wake of the rising bubble.

scholarly journals Ultra-high speed X-ray imaging of dynamic fracturing in cementitious materials under impact

2021 ◽  
Vol 250 ◽  
pp. 01014
Author(s):  
Bratislav Lukić ◽  
Maria Blasone ◽  
Yannick Duplan ◽  
Pascal Forquin ◽  
Emilio Escauriza ◽  
...  
Keyword(s):  
High Speed ◽  
High Strength ◽  
Cementitious Materials ◽  
Test Configuration ◽  
X Ray ◽  
Ultra High Speed ◽  
X Ray Imaging ◽  
Two Samples ◽  
Fragmentation Patterns ◽  
Dynamic Fracturing

In this work the dynamic fracturing of an ultra-high strength cementitious material is probed with in-situ ultra-high speed X-ray phase-contrast diagnostics to investigate the phenomenology of dynamic fracture. Gas gun experiments were conducted on two characteristic samples with two different impact speeds, namely 80 and 190 m/s using the edge-on impact test configuration. The samples were placed within the intense X-ray beam providing an observation field of 12.8 mm in width and 8 mm in height. Thanks to equispaced 16 bunches of short X-ray pulses, the samples were imaged through an indirect detector arrangement using the Shimadzu HPV-X2 camera lens-coupled to a fast scintillator capturing through-thickness measurements with an interframe time of 1.06 µs. The comparison of fragmentation patterns between two samples revealed an important insight into velocity dependant spall formation as well as the effects of crack closure and bridging.

scholarly journals Ultra-high-speed indirect x-ray imaging system with versatile spatiotemporal sampling capabilities

2018 ◽  
Vol 57 (18) ◽  
pp. 5004 ◽  
Author(s):  
Emilio M. Escauriza ◽  
Margie P. Olbinado ◽  
Michael E. Rutherford ◽  
David J. Chapman ◽  
John C. Z. Jonsson ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging System ◽  
X Ray ◽  
Ultra High Speed ◽  
X Ray Imaging

scholarly journals Ultra high-speed x-ray imaging of laser-driven shock compression using synchrotron light

2018 ◽  
Vol 51 (5) ◽  
pp. 055601 ◽  
Author(s):  
Margie P Olbinado ◽  
Valentina Cantelli ◽  
Olivier Mathon ◽  
Sakura Pascarelli ◽  
Joerg Grenzer ◽  
...  
Keyword(s):  
Shock Compression ◽  
High Speed ◽  
X Ray ◽  
Ultra High Speed ◽  
X Ray Imaging ◽  
Synchrotron Light

Advances in indirect detector systems for ultra high-speed hard X-ray imaging with synchrotron light

2018 ◽  
Vol 13 (04) ◽  
pp. C04004-C04004 ◽  
Author(s):  
M.P. Olbinado ◽  
J. Grenzer ◽  
P. Pradel ◽  
T. De Resseguier ◽  
P. Vagovic ◽  
...  
Keyword(s):  
High Speed ◽  
X Ray ◽  
Ultra High Speed ◽  
X Ray Imaging ◽  
Synchrotron Light
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