Influence of Thermal Effects and Material Disorder on Fracture Propagation

Crack propagation in heterogeneous materials is strongly influenced by the combined effects of temperature, microstructural disorder, and dissipation mechanisms, particularly in subcritical fracture regimes. Recent experiments performed on pressure-sensitive adhesive (PSA) tapes by S.Santucci et al at the École Normale Supérieure de Lyon (France) have revealed complex slow fracture dynamics, including intermittent and thermally activated propagation regimes under quasi-static loading conditions.

While these studies provide a detailed experimental characterization of adhesive peeling and fracture processes, the present work focuses on a theoretical investigation aimed at interpreting the underlying physical mechanisms observed experimentally. Within the framework of linear elastic fracture mechanics, we develop a model describing the time-dependent crack propagation kinetics by accounting for thermally activated processes and material disorder, in connection with energy-based approaches of the Griffith type. The model relates the elastic energy release rate and the stress intensity factor to the crack propagation velocity and allows us to analyze the influence of temperature on the transition from slow crack growth to unstable fracture. The results highlight the key role of thermal fluctuations in subcritical fracture processes and provide a consistent theoretical framework for interpreting experimental observations in adhesive materials.