Multiscale Modeling of Crack Formation in Composite Laminates with Manufacturing Defects

Abstract

As a part of a hybrid approach to composite materials damage and failure analysis combining synergistic damage mechanics and peridynamics, the work presented here deals with multiscale modeling of the formation of cracks. The failure events in a ply of a composite laminate are analyzed from the earliest stages induced by a brittle cavitation phenomenon to the emergence of a crack of a continuous plane. Manufacturing induced fiber distribution disorder is simulated by statistical methods. The loading condition considered is quasi-static transverse tension. The earliest failure event of brittle cavitation in an epoxy matrix causing fiber/matrix debonding is studied by molecular dynamics simulation to understand the effect of stress triaxiality. The energy release rates of debond cracks are examined in the presence of other fibers surrounding a debonded fiber to study the effect of interfiber spacing on the debond growth and its kinking out of the interface and eventually causing linkup with the neighboring debonds. The growth of a potential transverse crack in an environment of distributed fibers is studied by the J-integral method.