Crack-tip field at steady crack growth and vanishing linear strain-hardening.
A solution to the quasistatically propagating mode III crack in an elastic perfectly plastic solid is obtained as the limit solution for vanishingly small linear strain hardening. A point above or below the crack plane will experience, first, a centered fan slip line field followed at the angle ±32.8° ahead of the crack tip by elastic unloading and, finally, from the angle ±179.7° to the crack sur