Abstract
The image force and shielding effects of a moving edge dislocation near a semi-infinite crack were investigated. The crack surface was simulated by continuous dislocations. After the dislocation distribution in the crack was obtained, the stress field in the entire space was calculated. Based on the stress field, the stress intensity factor and crack extension force on the crack tip, and the image force on the edge dislocation were computed. The crack shielding or antishielding arising from the edge dislocation slip or climb was studied in detail. The transition velocity of changing behavior of edge dislocation and Lorentz force were discussed. Newton's third law was invalid in the system of moving edge dislocation and crack.