Effects of surface elasticity on mixed-mode fracture

Surface effects often significantly alter the physical and mechanical properties of nanosized materials and devices. In the present paper, we investigate the influence of surface elasticity on the mixed-mode fracture by a new finite element method with surface effects being incorporated. It is found that when the curvature radius at the crack root shrinks to nanometers, surface elasticity considerably affects the local stress distributions in the vicinity of the crack tip. Using the fracture criterion of maximum hoop stress, the influences of surface elasticity on the critical stress intensity factor and the propagation direction are addressed.