Abstract
Delayed fracture occurs in unidirectional composites as a result of accumulation of micro-damages, such as fiber breakage or time-dependent interfacial debonding. In this study, the creep rupture lifetime in unidirectional composites is predicted under consideration of the propagation of interfacial debonding and its effect on rupture lifetime and damage accumulation is examined. Predictions were performed for two cases that stress concentration on intact fiber adjacent to broken fiber is not taken into account or taken into account. For former case, the decrease in rupture strain due to time-dependent propagation of interfacial debonding is formulated. For latter case, Monte-Carlo simulation under consideration of interfacial debonding propagating fiber breakage point is performed. As a result, the propagation of stress concentration region is observed and it is thought to be dominant factor for time-dependent damage accumulation in unidirectional composites.
