Simulations of Carbon Fiber Composite Delamination Tests

摘要

Initiation and propagation of interlaminar failure (delamination) in fiber composites is of paramount importance in predicting the failure of composite structures. A program to simulate the performance of aircraft composite material as uncontained engine fragment barriers has been initiated and supported by the Federal Aviation Administration (FAA). Predicting the delamination between lamina of a carbon-reinforced composite during penetration by test fragments is an important part of that FAA program. Simulations of mode I interlaminar fracture toughness tests of a carbon-reinforced composite material (BMS 8-212) were conducted with LSDYNA. The fracture toughness tests were performed by University of California, Berkeley. The simulations were performed to investigate the validity and practicality of employing decohesive elements to represent interlaminar bond failures that are prevalent in carbon-fiber composite structure penetration events. The simulations employed a decohesive element formulation that was verified on a simple, two-element model before being employed to perform the full model simulations. Care was required during the simulations to ensure that the explicit time integration of LSDYNA duplicate the near steady-state testing conditions.