The screw dislocations near an interfacial cross crack are investigate
d. The stress field, stress intensity factor, image force, and strain
energy of screw dislocations are derived based on the solution of a si
ngle medium. The effects of vertical and horizontal crack lengths on t
he stress intensity factor at the upper crack tip and image force comp
onents F(x) and F(y) are examined. The dislocation source is also stud
ied.