Dynamic fracture analysis by moiré interferometry

Dynamic moiré interferometry was used to measure separately the u- and v-displacement fields surrouding a rapidly propagating crack tip in Homalite-100 and 7075-T6 aluminum-alloy plates. These transient crack-tip-displacement data were then used to compute the dynamic stress-intensity factor and the remote stress component. J-integral values were also estimated using the static approximate procedure of Kang et al. This static analysis provided the correct J when the contour integral was taken within 3 mm of the crack tip.