A Study on Dynamic Crack-Tip Fields in a Strain Softening Material

The near-tip field of mode-I dynamic cracks steadily propagating in a strain softening material is investigated under plane strain conditions. The material is assumed to be incompressible and its deformation obeys the <TEX>$J_2$</TEX> flow theory of plasticity. A power-law stress-strain relation with strain softening is adopted to account for the damage behavior of materials near the dynamic crack tip. By assuming that the stresses and strain have the same singularity at the crack tip. this paper obtains a fully continuous dynamic crack-tip field in the damage region. Results show that the stress and strain components the same logarithmic singularity of (In(R/r))<TEX>$delta$</TEX>, and the angular variations of filed quantities are identical to those corresponding to the dynamic cracks in the elastic-perfectly plastic material.