Strength analysis and failure prediction of thin tow-based discontinuous composites

Abstract

Tow Based Discontinuous Composites (TBDCs) are a new class of composite materials which combine in-plane isotropy, high strength and stiffness and enhanced manufacturability. However, due to their complicated micro-architecture, characterising the performance of these materials and predicting their response is challenging. This work develops a complete experimental and analytical framework which identifies all the key properties in the performance of the TBDCs, characterises them experimentally and builds an analytical predictive tool for both the stiffness response and the strength of the TBDC material. Fractography is also utilised to identify the damage mechanisms and correlate them with the analytical predictions. A parametric study is developed which shows the critical effect that the tape thickness and mode II fracture toughness have on the TBDCs. Finally, the performance of the material is compared to similarly developed TBDCs from the literature and shows the significant strength and stiffness increases recorded through the combination of the thin high-modulus tapes and the increased fibre volume fractions.