scholarly journals A numerical study of the influence from pre-existing cracks on granite rock fragmentation at percussive drilling

2014 ◽  
Vol 39 (5) ◽  
pp. 558-570 ◽  
Author(s):  
Mahdi Saadati ◽  
Pascal Forquin ◽  
Kenneth Weddfelt ◽  
Per-Lennart Larsson ◽  
Francois Hild
Keyword(s):  
Numerical Study ◽  
Rock Fragmentation ◽  
Percussive Drilling ◽  
Granite Rock

Granite rock fragmentation at percussive drilling

2013 ◽  
pp. 437-442
Author(s):  
M Saadati ◽  
P Forquin ◽  
K Weddfelt ◽  
P Larsson
Keyword(s):  
Rock Fragmentation ◽  
Percussive Drilling ◽  
Granite Rock

Thermal jet drilling of granite rock: a numerical 3D finite-element study

2021 ◽  
Vol 379 (2196) ◽  
pp. 20200128
Author(s):  
Timo Saksala ◽  
Reijo Kouhia ◽  
Ahmad Mardoukhi ◽  
Mikko Hokka
Keyword(s):  
Finite Elements ◽  
Numerical Study ◽  
Thermal Flux ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Mass Scaling ◽  
Granite Rock ◽  
Fracture Dynamics ◽  
Rock Heterogeneity ◽  
Thermal Drilling

This paper presents a numerical study on thermal jet drilling of granite rock that is based on a thermal spallation phenomenon. For this end, a numerical method based on finite elements and a damage–viscoplasticity model are developed for solving the underlying coupled thermo-mechanical problem. An explicit time-stepping scheme is applied in solving the global problem, which in the present case is amenable to extreme mass scaling. Rock heterogeneity is accounted for as random clusters of finite elements representing rock constituent minerals. The numerical approach is validated based on experiments on thermal shock weakening effect of granite in a dynamic Brazilian disc test. The validated model is applied in three-dimensional simulations of thermal jet drilling with a short duration (0.2 s) and high intensity (approx. 3 MW m −2 ) thermal flux. The present numerical approach predicts the spalling as highly (tensile) damaged rock. Finally, it was shown that thermal drilling exploiting heating-forced cooling cycles is a viable method when drilling in hot rock mass. This article is part of the theme issue ‘Fracture dynamics of solid materials: from particles to the globe’.

A numerical study of the impact of short delays on rock fragmentation

2017 ◽  
Vol 100 ◽  
pp. 250-254 ◽  
Author(s):  
Changping Yi ◽  
Jonny Sjöberg ◽  
Daniel Johansson ◽  
Nikolaos Petropoulos
Keyword(s):  
Numerical Study ◽  
Rock Fragmentation ◽  
The Impact

Numerical study on impact energy transfer and rock damage mechanism in percussive drilling based on high temperature hard rocks

Geothermics ◽  
2021 ◽  
Vol 96 ◽  
pp. 102215
Author(s):  
Hengyu Song ◽  
Huaizhong Shi ◽  
Zhenliang Chen ◽  
Gensheng Li ◽  
Ran Ji ◽  
...  
Keyword(s):  
Energy Transfer ◽  
High Temperature ◽  
Impact Energy ◽  
Numerical Study ◽  
Damage Mechanism ◽  
Rock Damage ◽  
Percussive Drilling ◽  
Hard Rocks

Numerical Study of the Rock Fragmentation by Three TBM Cutters

2012 ◽  
Vol 594-597 ◽  
pp. 3-7
Author(s):  
Yan Wang ◽  
Zheng Zhao Liang
Keyword(s):  
Numerical Study ◽  
Rock Breaking ◽  
Rock Fragmentation ◽  
Numerical Code ◽  
Time Interval ◽  
The Finite Element Method ◽  
Whole Process ◽  
Disc Cutters ◽  
Initiation And Propagation ◽  
Damage Theory

Based on the mesoscopic damage theory and the finite element method, a numerical code RFPA was applied to investigate the rock fragmentation by three TBM cutters loaded one after another in different time interval. The whole process of crack initiation and propagation was successfully simulated by the cutters loaded with different step intervals. The time interval of the disc cutters has significant influence on the fracture patterns and the rock breaking efficiency. The simulated results show that there are three types of breakage mode of the rock subjected to compression by the cutters.

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