Rupture front propagation along a bimaterial interface: new experimental insights

We present new experimental results describing rupture fronts that propagate at both sub-Rayleigh and supershear velocities along a rough bi-material interface. These results are obtained by means of simultaneous real-time measurements of the real contact area and all components of the strain tensor along a long, spatially extended interface, when a material contrast of approximately 20-30% is imposed. A number of qualitatively different rupture fronts are observed. The rupture velocities selected by the system and the rupture form highly depend on the rupture direction relative to the slip direction. We will present detailed measurements of the structure of these different rupture fronts and provide a quantitative comparison to rupture front measurements performed on a homogeneous (no material contrast) interface. Many of these results suggest qualitative agreement with current theoretical predictions.