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SUMMARY:Pressure and stress fluctuations in fracturing saturated porous me
 dia
DTSTART:20141024T121500
DTEND:20141024T131500
DTSTAMP:20260506T143937Z
UID:9246a0f85811d6be3dfc23ddb26c67c75d01fde0b60238568b876ba0
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Bernhard Schrefler\, University of Padua\, Italy\nWith E
 . Milanese\, P. Rizzato\, J.M.R. Huyghe\, J.F. Molinari\, S. Secchi\, L. S
 imoni\nThe pressure and stress evolution in fracturing saturated porous me
 dia is investigated on meso-mechanics and macro-mechanics level. Crack pro
 pagation under external loading (peel test and biaxial loading)\, assigned
  pressure and assigned flux (fracking) is considered. For meso-mechanics i
 nvestigations a lattice model is used which has been introduced in a Biot-
 type formulation. The avalanche behaviour of the cracking events is eviden
 ced.\nAt macro mechanics level both standard Finite Elements with remeshin
 g and appropriate crack-tip advancement algorithm\, and XFEM are used. A c
 ohesive fracture model is adopted together with a discrete crack approach 
 and without predetermined fracture path. The Rankine criterion is used for
  fracture nucleation and advancement. In the standard FE approach the frac
 ture follows in a 2D setting directly the direction normal to the maximum 
 principal stress while in the 3D case the fracture follows the face of the
  element around the fracture tip closest to the normal direction of the ma
 ximum principal stress at the tip. This procedure requires continuous upda
 ting of the mesh around the crack tip to take into account the evolving ge
 ometry. The updated mesh is obtained by means of an efficient mesh generat
 or based on Delaunay tessellation [1\, 2\, 3]. Comparison is made with the
  XFEM method. The governing equations for all approaches are written in th
 e framework of porous media mechanics and are solved numerically in a full
 y coupled manner. Numerical examples include well injection (constant infl
 ow) in a geological setting\, hydraulic fracture in 2D and 3D concrete dam
 s (increasing pressure) and a peeling test for a fully saturated porous me
 dium\; stepwise tip advancement and pressure oscillations are shown. A com
 parison with results found in literature and with the solutions obtained w
 ith the XFEM method evidences the shortcomings of methods like PUFEM\, XFE
 M and Phase Field methods when used in their traditional way for the simul
 ation of the coupled phenomena going on at the crack tip.\nBio: Bernhard A
 . Schrefler holds a ME degree from the University of Padua and a PhD and D
 Sc from the Swansea University\, Wales. He is Secretary General of the Int
 ernational Centre for Mechanical Sciences in Udine\, Professor Emeritus of
  the University of Padua and Senior Affiliate Member of the Houston Method
 ist Research Institute\, TX. For his research work Dr. Schrefler has been 
 awarded the Maurice A. Biot Medal from ASCE\, the Euler Medal from ECOMAS\
 , the Computational Mechanics Award from IACM\, the IACM Award and the Pal
 mes Académiques in France. He has received honorary doctorates from the S
 t. Petersburg State Technical University\, the University of Technology of
  Lodz\, the Leibniz University of Hannover\, the Russian Academy of Scienc
 es and the Ecole Normale Supérieure at Cachan\, an honorary fellowship fr
 om the University of Wales Swansea and an honorary professorship from the 
 Dalian University of Technology. Dr. Schrefler is member of the National (
 Italian) Academy of Sciences\, of the Accademia Galileiana di Scienze\, Le
 ttere ed Arti and of the Istituto Veneto di Scienze\, Lettere ed Arti.
LOCATION:GC A331 http://plan.epfl.ch/?lang=fr&room=GC+A3+31
STATUS:CONFIRMED
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