Interlaminar fracture of asymmetrically delaminated specimens: beam modelling and noteworthy characteristics

Abstract

Despite providing interesting mode‐mix ratios without elaborate test fixtures, asymmetrically delaminated specimens have been scarcely used for characterizing delamination resistance. This is mostly due to the elaborate analyses employed and the controversy about mode partitioning. This paper presents a beam model for asymmetrically delaminated unidirectional composite specimens. The physical meaning and underlying assumptions of the solutions obtained are clearly identified. Comparison with finite element analyses showed that the present beam model is accurate for a wide range of asymmetry and mode‐mix ratios. Since it does not require complicated calculations, the beam model is well‐suited for experimental data reduction. Furthermore, traction distributions near the crack‐tip were found to differ from those of standard specimens, thereby increasing the interest in studying the fracture behaviour of asymmetrically delaminated specimens.