Test methodCombining displacement, strain, temperature and heat source fields to investigate the thermomechanical response of an elastomeric specimen subjected to large deformations

Combining thermal and kinematic full-field measurements at the same time is gaining widespread acceptance in the community involved in the thermomechanical characterization of materials. However, obtaining such attractive information in the case of elastomers for which large deformations occur raises specific experimental issues which are addressed in this paper. The problem arises in mapping both the thermal and the kinematic quantities in the same reference coordinate system in order to write properly the heat diffusion equation. This equation provides heat sources which constitute a relevant quantity in the framework of thermomechanics. The procedure is presented and the underlying practical difficulties are detailed. It is then applied in the case of a specific test performed on a so-called three-branch specimen. Finally, the obtained strain and heat source distributions are briefly discussed.