Experimental and numerical analysis of Carbon Fiber Reinforced Polymer notched coupons under tensile loading

The behavior of composite laminates subject to notch based stress concentrations is difficult to apprehend, especially the mechanisms of damage progression leading to total failure. Numerical and experimental investigations were carried out on three different stacking sequences of notched, thin ply carbon/epoxy laminates. This paper presents a computational study of notched tensile tests (U-notch) using the Discrete Ply Modeling (DPM) method, which has already proved efficient on both in-plane and out-of-plane loading cases, such as pull through, low velocity impact and compression after impact. The specificities of this finite element model are its discrete nature (interface elements to model delamination and matrix cracks), the small number of parameters required, and its robustness. This work follows on from the study of open-hole tensile tests (same three layups) by the same authors [1] and analyzes the influence of layup and notch shape. Comparisons with experiments (using infrared technology) demonstrate that tensile strengths, and failure scenarios and patterns are predicted with acceptable accuracy.