Simulation of fracture tests on notched composite plates

Abstract

Size effects influence the behavior of composites and have a great effect on their properties such as strength, type of failure, etc. The effects of size of the specimen on the behavior of composite laminates were studied based on numerical analyses of sharp and blunt notched [45/90/-45/0] 4s carbon/epoxy composite laminates. Five different numerical models in each notch case with in-plane dimensions scaled up to a factor 16 were analyzed. The computational framework adopted in the study uses phantom node method for modelling matrix cracks, continuum damage model for fibre failure and interface elements for de- lamination. The capability of the framework to capture the size effects in the failure load and failure mechanisms of composite laminates with both sharp and blunt notches was assessed. The damage zone properties captured through CT images from interrupted tests were compared with the results obtained from numerical simulations. Parametric studies were carried out on the numerical models to match the simulation and the experimental results. The observations from the study revealed that there is a good correlation between the experimental and simulation results. The computational framework used in the study predicts the strengths of composite laminates, replicates size effects in the laminates and the failure mechanisms accurately.