... ESCUDIE DANY CHARGE DE RECHERCHE CNRS FERRAND Pascal HENRY Daniel LE PENVEN Uonel ... à tous ... more ... ESCUDIE DANY CHARGE DE RECHERCHE CNRS FERRAND Pascal HENRY Daniel LE PENVEN Uonel ... à tous les membres (permanents ou non) du Département de Mécanique des Solides, en particulier Madame Marie CHAZE et Monsieur Alexandre DANESCU, pour leur ...
Debris flows (DFs) are dangerous events that can cause the complete destruction of buildings and ... more Debris flows (DFs) are dangerous events that can cause the complete destruction of buildings and infrastructure, such as bridges; DFs therefore represent a high risk to public safety in exposed areas. The impact pressures due to these flows are essentially determined by the flow height, velocity and density, but other parameters that are less often considered are also involved. We developed a numerical model to evaluate the impact pressure of mass flows, focusing on a better description of the influence of the blocks transported in these flows: the block size strongly influences the impact pressure, which has a strong effect on structural damage. The numerical model proposed considers a staggered, loosely one-way granular–fluid coupling based on a distinct-element-method code, using the separate simulation results of a computing fluid dynamics code used to model the fluid phase. This model estimates the impact pressure distribution due to blocks at the local scale of the obstacle; t...
A crack-resistant carbon anode in high-amperage aluminium cells contributes to improved cell stab... more A crack-resistant carbon anode in high-amperage aluminium cells contributes to improved cell stability and reduced operational costs. Increased metal production by current increase programs is less challenging, and energy savings by deeper anode slots are possible. As an effort to search an improved guidance in the anode manufacturing process and in the raw material selection, new and modified physical quality parameters, based on physical loading tests and finite element analysis, are introduced. Namely, an improvement to the measurement of fracture toughness along with new parameters characterizing the non-linearity in observed stress-strain curves are presented. A cooperation between Itasca Consultants and Hydro has been established to develop a particle-based model using the Discrete Element Method, aiming to study the relationship between the microstructure and the macroscopic mechanical properties and quality parameters of the carbon anode. The model is being developed in the ...
This paper focuses on the city of Arequipa (Peru), located 17 km of the summit of the El Misti vo... more This paper focuses on the city of Arequipa (Peru), located 17 km of the summit of the El Misti volcano. Arequipa is exposed to many natural hazards, linked to the presence of volcanic ash and heavy rains occurring at the beginning of the year, ideal conditions to form lahars. This city hosts poor populations who mainly benefit from rudimentary masonry facilities. These infrastructures suffer from disorderly and poorly planned growth which makes them weak points when debris impact them (Mead 2017).
Les massifs rocheux sont des milieux généralement discontinus et hétérogènes et souvent anisotrop... more Les massifs rocheux sont des milieux généralement discontinus et hétérogènes et souvent anisotropes. Leur comportement dépend aussi bien de la matrice rocheuse que des discontinuités initialement présentes dans le massif ou se formant au cours de leur histoire. La mécanique complexe qui en résulte est souvent difficilement prévisible sans l’apport des modèles numériques continus et/ou discontinus.
Constitutive Modelling of Granular Materials, 2000
This paper deals with different ways to performe a change of scale in granular materials. Two dif... more This paper deals with different ways to performe a change of scale in granular materials. Two different local levels are considered and analysed: the local level defined at the contacts between particles and the local level defined at the local array level. The difficulties to perform a change of scale, considering these two local levels are analysed and discussed. The different theoretical approaches presented in this paper are illustrated by a numerical simulation using a DEM code.
The stimulation of the deep wells drilled in the Soultz-sous-Forêts geothermal site (France) by t... more The stimulation of the deep wells drilled in the Soultz-sous-Forêts geothermal site (France) by the injection of cold and pressurised water demonstrates that the access zones of the fluid to the fracture network is limited to a few fractures. In the near well at the scale of some meters, a decrease of the impedancy is outlined via hydraulic vibration tests
In order to study the thermo-mechanical effects induced by the injection of a fluid like CO2 in a... more In order to study the thermo-mechanical effects induced by the injection of a fluid like CO2 in a host rock whose temperature is higher than those of the fluid, a DEM modeling has been imple-mented based on a "particulate" approach (Particle Flow code - PFC). The methodology devel-oped to build a particle rock model consistent with the rock petrophysical characteristics and the thermo-mechanical behavior is proposed in this paper. The three main steps are described: rock conceptualization (association of rock petrophysical and textural elements with numerical ob-jects), estimating geometrical and physical properties of the rock model from the petrographic characteristics, and finally mechanical and thermo-mechanical calibration. An example of a modeling of drilling mechanical effect and thermo-mechanical effects induced by injection of a cold fluid in a host rock is finally presented.
... ESCUDIE DANY CHARGE DE RECHERCHE CNRS FERRAND Pascal HENRY Daniel LE PENVEN Uonel ... à tous ... more ... ESCUDIE DANY CHARGE DE RECHERCHE CNRS FERRAND Pascal HENRY Daniel LE PENVEN Uonel ... à tous les membres (permanents ou non) du Département de Mécanique des Solides, en particulier Madame Marie CHAZE et Monsieur Alexandre DANESCU, pour leur ...
Debris flows (DFs) are dangerous events that can cause the complete destruction of buildings and ... more Debris flows (DFs) are dangerous events that can cause the complete destruction of buildings and infrastructure, such as bridges; DFs therefore represent a high risk to public safety in exposed areas. The impact pressures due to these flows are essentially determined by the flow height, velocity and density, but other parameters that are less often considered are also involved. We developed a numerical model to evaluate the impact pressure of mass flows, focusing on a better description of the influence of the blocks transported in these flows: the block size strongly influences the impact pressure, which has a strong effect on structural damage. The numerical model proposed considers a staggered, loosely one-way granular–fluid coupling based on a distinct-element-method code, using the separate simulation results of a computing fluid dynamics code used to model the fluid phase. This model estimates the impact pressure distribution due to blocks at the local scale of the obstacle; t...
A crack-resistant carbon anode in high-amperage aluminium cells contributes to improved cell stab... more A crack-resistant carbon anode in high-amperage aluminium cells contributes to improved cell stability and reduced operational costs. Increased metal production by current increase programs is less challenging, and energy savings by deeper anode slots are possible. As an effort to search an improved guidance in the anode manufacturing process and in the raw material selection, new and modified physical quality parameters, based on physical loading tests and finite element analysis, are introduced. Namely, an improvement to the measurement of fracture toughness along with new parameters characterizing the non-linearity in observed stress-strain curves are presented. A cooperation between Itasca Consultants and Hydro has been established to develop a particle-based model using the Discrete Element Method, aiming to study the relationship between the microstructure and the macroscopic mechanical properties and quality parameters of the carbon anode. The model is being developed in the ...
This paper focuses on the city of Arequipa (Peru), located 17 km of the summit of the El Misti vo... more This paper focuses on the city of Arequipa (Peru), located 17 km of the summit of the El Misti volcano. Arequipa is exposed to many natural hazards, linked to the presence of volcanic ash and heavy rains occurring at the beginning of the year, ideal conditions to form lahars. This city hosts poor populations who mainly benefit from rudimentary masonry facilities. These infrastructures suffer from disorderly and poorly planned growth which makes them weak points when debris impact them (Mead 2017).
Les massifs rocheux sont des milieux généralement discontinus et hétérogènes et souvent anisotrop... more Les massifs rocheux sont des milieux généralement discontinus et hétérogènes et souvent anisotropes. Leur comportement dépend aussi bien de la matrice rocheuse que des discontinuités initialement présentes dans le massif ou se formant au cours de leur histoire. La mécanique complexe qui en résulte est souvent difficilement prévisible sans l’apport des modèles numériques continus et/ou discontinus.
Constitutive Modelling of Granular Materials, 2000
This paper deals with different ways to performe a change of scale in granular materials. Two dif... more This paper deals with different ways to performe a change of scale in granular materials. Two different local levels are considered and analysed: the local level defined at the contacts between particles and the local level defined at the local array level. The difficulties to perform a change of scale, considering these two local levels are analysed and discussed. The different theoretical approaches presented in this paper are illustrated by a numerical simulation using a DEM code.
The stimulation of the deep wells drilled in the Soultz-sous-Forêts geothermal site (France) by t... more The stimulation of the deep wells drilled in the Soultz-sous-Forêts geothermal site (France) by the injection of cold and pressurised water demonstrates that the access zones of the fluid to the fracture network is limited to a few fractures. In the near well at the scale of some meters, a decrease of the impedancy is outlined via hydraulic vibration tests
In order to study the thermo-mechanical effects induced by the injection of a fluid like CO2 in a... more In order to study the thermo-mechanical effects induced by the injection of a fluid like CO2 in a host rock whose temperature is higher than those of the fluid, a DEM modeling has been imple-mented based on a "particulate" approach (Particle Flow code - PFC). The methodology devel-oped to build a particle rock model consistent with the rock petrophysical characteristics and the thermo-mechanical behavior is proposed in this paper. The three main steps are described: rock conceptualization (association of rock petrophysical and textural elements with numerical ob-jects), estimating geometrical and physical properties of the rock model from the petrographic characteristics, and finally mechanical and thermo-mechanical calibration. An example of a modeling of drilling mechanical effect and thermo-mechanical effects induced by injection of a cold fluid in a host rock is finally presented.
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