High speed imaging based measurement of dynamic crack speed in PDMS

This proof-of-concept study demonstrates the application of using high-speed imaging to measure dynamic crack speed in soft materials. Given the low modulus of these materials, crack speeds are modest (10–15 m/s), allowing a standard laboratory high-speed camera to capture successive images of crack propagation. By processing these images, the crack tip position can be tracked to calculate instantaneous crack velocity. This approach is demonstrated with PDMS, a common elastomer. Dynamic cracks are initiated through preloading rectangular specimens under uniaxial tension and creating a nick on the specimen's edge with a blade. The resulting dynamic crack propagation, captured in real-time, reveals velocity behavior consistent with previous findings, displaying an initial acceleration followed by a steady-state phase. The measured velocities align with values reported in the literature, validating this accessible technique as a promising tool for further exploration of crack dynamics in soft materials.