Abstract
The dislocation-modeling technique and complex variable method are used to analyze the interaction between the general parallel screw dislocations and a surface crack. For the case of one dislocation, the dislocation distribution in the crack, the stress field, the strain energy, the image force, the stress intensity factor, and the crack extension force are obtained. The results are compared with various special cases of other papers. Under the applied stress without the frictional force, there are two metastable points and no stable point in the strain energy diagram. Therefore, the dislocation will move to the free surface, crack surface, or infinity depending on its location. The two-dislocation system or the even dislocation dipole is analyzed. Although this approach gets the same results as the conformal mapping method, the former is superior in analyzing two or more dislocations.