Abstract
Interface debonding and its effect on crack stability in a single-edge-notched PMMA/glass bi-material have been studied. Direct observation of crack growth behavior is carried out and crack tip stress intensity factor during crack growth process is obtained by a laser Caustics method. Interface stress distribution at the onset of interface debonding is obtained by FEA with experimentally obtained stress/strain conditions. The interface debonding ahead of a growing crack tip occurs before the crack reaches the interface. A transition from slow to rapid crack growth is predicted by the event of an interface debonding ahead of a growing crack tip. This debonding is caused by an interface tensile stress. The maximum interface tensile stress obtained by FEA with experimental boundary condition, σd, and the distance between the crack tip and interface at the onset of interface debonding, x0, follows the relation, σd=Ad⁄\sqrtx0. This relation provides the condition for the interface tensile debonding. The condition suggests that the interface tensile debonding has a probabilistic nature.
