Numerical study of size effects in micro/nano plates by moving finite elements

2019 ◽  
Vol 212 ◽  
pp. 291-303 ◽  
Author(s):  
M. Repka ◽  
V. Sladek ◽  
J. Sladek
Keyword(s):  
Finite Elements ◽  
Size Effects ◽  
Numerical Study ◽  
Moving Finite Elements

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’.

Numerical Study of the Influence of the Crack Front Curvature in the Evolution of the Plastic Zone along the CT Specimen Thickness

2011 ◽  
Vol 465 ◽  
pp. 119-122 ◽  
Author(s):  
Daniel Camas ◽  
Pablo Lopez-Crespo ◽  
Antonio González-Herrera
Keyword(s):  
Fatigue Crack ◽  
Finite Elements ◽  
Plastic Zone ◽  
Crack Closure ◽  
Crack Front ◽  
Numerical Study ◽  
Load Level ◽  
Specimen Thickness ◽  
Aluminum Specimen ◽  
Front Curvature

This paper presents a numerical study of the influence of the load level and the crack front curvature on the plastic zone in the area close to the crack front. The aim of the work is to determine the influence of these parameters on fatigue crack closure. For this, a CT aluminum specimen has been modelled tri-dimensionally and several finite elements calculations have been made considering a large combination of the variables under consideration.

Moving Finite Elements. II

1981 ◽  
Vol 18 (6) ◽  
pp. 1033-1057 ◽  
Author(s):  
Keith Miller
Keyword(s):  
Finite Elements ◽  
Moving Finite Elements

Composition and Size Effects on the Optical Properties of Isolated Silicon-Germanium Nanowires

2012 ◽  
Vol 1408 ◽  
Author(s):  
Houssem Kallel ◽  
Abdallah Chehaidar ◽  
Arnaud Arbouet ◽  
Thierry Baron ◽  
Alexis Potié ◽  
...  
Keyword(s):  
Optical Properties ◽  
Silicon Germanium ◽  
Size Effects ◽  
Numerical Study ◽  
Mie Theory ◽  
Light Polarization ◽  
Angle Of Incidence ◽  
Nanowire Diameter ◽  
Germanium Nanowires ◽  
Silicon And Germanium

ABSTRACTSilicon and Germanium nanowires (NWs) have shown a strong ability to enhance both the absorption and scattering of light. Tailoring the optical properties of Si or Ge NWs can be obtained by adjusting the nanowire diameter. Another parameter that can be used is the chemical composition of silicon-germanium (Si1-xGex-NWs) alloys. In this work, we perform a numerical study on the optical properties of single Si1-xGex-NWs based on the Lorenz-Mie theory. The effects of Ge composition, light polarization and angle of incidence on the nanowire optical properties are investigated.

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