Numerical simulations of embedded wrinkle defects geometry on the strength knockdown of FRP composites

With the wide adoption of composite materials for a variety of applications, the prediction of their failure remains a challenging prospect. To complicate this scenario, out-of-plane fibre waviness defects, also known as wrinkle defects, are a major type of manufacturing defects that can degrade the mechanical performances of continuous carbon fibre composite panels, especially their compressive strength. In this work, the effects of such defects on square composite specimens are addressed through Finite Element (FE) analysis. A Matlab-Abaqus FE routine is proposed, which is capable of generating a wide variety of composite specimens with several types of embedded wrinkles and a number of controllable parameters. Parametric analyses are then performed to investigate the effects of defects characteristics on the knockdown in compressive strength, and several conclusions are drawn. Results show that is possible to determine the dependence of compressive strength on various wrinkle parameters such as amplitude or angle.