ISTerre seminar

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Strain-rate, temperature, and stress in ice: from classical to near-equilibrium thermodynamic formulations

Thursday 5 February 2026 - 11h00

Mehdi Pouragha - Carleton University, Ottawa, Canada
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Understanding how ice deforms and fails across a wide range of temperatures, pressures, and loading rates continues to pose challenges for constitutive modelling. In the first part of this talk, I will present a formulation we refer to as a thermo-baro-kinetic model for polycrystalline ice. This formulation builds on earlier work by Dansereau et al. for sea ice, extending those ideas toward a unified representation of creep and fracture under thermomechanical loading. The model couples nonlinear creep and damage evolution through shared dependencies on stress, temperature, and strain rate, allowing it to reproduce observed trends such as rate-dependent strengthening, thermal softening, pressure effects, and stress relaxation. The aim is not to claim completeness, but to examine how far a compact, thermodynamically grounded set of kinetic relations can go in representing key aspects of ice behaviour. The second part of the talk briefly examines how these ideas may be transferred to ice-bonded granular materials, where grains and evolving ice bonds jointly govern the response. By combining granular contact mechanics with the thermo-baro-kinetic behaviour of ice, the resulting mixture model offers a way to interpret how macroscopic strength and failure modes might emerge from coupled bond degradation and granular rearrangement. In the final part, I will outline an ongoing effort to develop a near-equilibrium thermomechanical model for ice that invokes concepts such as a configurational temperature and the associated “energy-buffer’’ role it plays to provide a more physically meaningful description of rate-dependency and its interplay with temperature.

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Organizing team : Mécanique des failles

Amphithéâtre Killian, Maison des Géosciences, 38400 Saint Martin d'Hères

Informations de visio :

https://univ-grenoble-alpes-fr.zoom.us/j/96442674297?pwd=8BAIHH5Srl4OZngc3Pe4aqytupWndy.1