Notched tensile strength of long discontinuous glass fiber reinforced nylon composite

Abstract

In this study, the hole size effect in the open hole tension (OHT) of discontinuous glass fiber-polyamide 6 organosheet composite material was studied. Organosheet used in this study is a novel long discontinuous fiber-reinforced polymer composite with long glass fiber and in-situ polymerized polyamide 6 (nylon) matrix. A progressive failure analysis (PFA) using finite-element model was proposed to predict OHT strength using measured fiber orientation distribution. The generated virtual ogranosheet samples were used to conduct OHT Monte Carlo simulations to predict variability in strength. The notch sensitivity was observed experimentally and analyzed using PFA model, which captured interactions between various failure modes. The experimental and PFA results of OHT strength were used for calibrating analytical models, Point Stress Criterion (PSC) and Modified Point Stress Criterion (MPSC). Both, experimental and modeling approaches, yielded nearly identical analytical curves, indicating that virtual testing of organosheet can be used for OHT characterization of organosheet. The results show that the notched strength of organosheet with the diameter of 2 mm was at the same level as strength of unnotched organosheet. The notch insensitivity was attributed to the increased plasticity in the matrix due to ductility in nylon.