Ply-Orientation Dependence of Notched Strength of Multidirectional CFRP Laminates and Prediction Using a Finite Fracture Mechanics Model

摘要

A method for predicting the fracture toughness of a given laminate of any stackingsequence on the basis of the fracture toughness values of the constituent plies isproposed. This method is combined with the finite fracture mechanics (FFM) model topredict the notched strengths of multidirectional laminates with balanced off-axislayers. Static tension tests are carried out on the specimens with a circular open holefor different values of hole-diameter to specimen-width ratios, respectively. The angleplylaminates exhibit different notch sensitivities depending on their stackingsequences. The use of the ply-based fracture toughness values of laminates with theFFM model predicts slightly smaller values of notched strength compared with theexperimental results, regardless of notch size. The accuracy of prediction using theFFM model can be improved by taking into account the energy release due to localdelimitation.