Intervention : Stéphane André , Jing Ye, Neveu Alain, Farge Laurent, Stephane Andre

Thermomechanical investigation of solid materials using InfraRed imaging requires an inverse treatment of the temperature field to produce the intrinsic heat source field. Generally this is made assuming pure diffusion of heat which is valid in the regime of low Peclet numbers. In the case of plastic instabilities like the necking phenomenon observed when cold-drawing semi-crystalline polymers, the presence of non negligible advection is possible. which can produce a bias in the heat source reconstruction. It is then necessary to (i) measure precisely the velocity field during an experiment and (ii) use these data along with the measured temperature field to allows for a correct characterization of thermomechanical effects. We first discuss some experimental difficulties related to the measurement of velocity fields using DIC. A strategy is then presented that allows for heat source reconstruction in the diffusion-advection case.

Mis à jour le 27/05/2013