Property modellingModelling ENF test procedure by means of the two-step extension method. Influence of friction forces

This paper deals with the numerical determination of mode II energy release rate in AS4/8552 unidirectional carbon fibre/epoxy laminates. The Two-Step Extension Method is reviewed as an alternative procedure to perform Finite Element Analysis (FEA) on mode II delamination tests. The influence of some variables such as element length, type of element and 2D versus 3D models on the results was studied. Results were compared with empirical data obtained from End Notched Flexure (ENF) tests carried out on unidirectional carbon/epoxy laminates. In order to detect outliers, two statistical methods were used to validate the experimental results. Finally, the influence of the friction forces on the numerical results has been addressed.