This study considered the behavior of tensile and fatigue damage, and the effect of reinforcement of the interface strength given to a damage process by observing the microscopic damage to the fiber interface of glass fiber reinforcement polycarbonate. As a result, the following thing became clear. 1) In both tensile and fatigue process, damage was initiated from the fiber end in the early stages, and the debonding propagated along the fiber interface. 2) The GF/PC interface strength improved by adding the epoxy resin. 3) The debonding along the fiber interface was inhibited by improving interface strength.
