A detailed composite textile meso-level finite element failure modelling technique

Abstract

The specific contribution of this thesis is to present a detailed FE modelling approach to simulate the stiffness behaviour 3D fibre reinforced composites and facilitate progression to failure using commercially available software and existing computational capabilities. The composite constituents including the fibre, interface and resin regions are modelled with Tetrahedral, Pyramid and Hexahedral finite elements respectively. An analysis detailing the how geometric details such as inter tow spacing contribute to a models predictive performance is formed with increasing resin thicknesses reducing the elastic modulus. It is demonstrated that an elliptical tow shape is preferable for modelling 2D woven composites such as the plain weave and a racetrack tow shape is preferable for modelling 3D woven composites, with a 10% error between predicted and manufactured modulus values. The implications of modelling on the micro level are established, with the tow sub division into filaments shown to reduce model stiffness. Further geometrical considerations along with numerical factors such as the trade off between reducing the element number and increasing the accuracy of the geometry representation are also detailed.

A large catalogue of 3D fibre reinforced composite structures exists but their behaviourunder in-plane loading conditions is not fully understood. As the manufacturingtechnology associated with production of 3D woven structures becomes moresophisticated, the types of 3D reinforcing architectures that can be produced willincrease. The need therefore exists for the capability to predict the mechanicalperformance of fibre reinforced composite materials.

Date of Award	Feb 2011
Original language	English
Sponsors	Rolls-Royce & Department for Employment and Learning (DEL)
Supervisor	Alistair McIlhagger (Supervisor) & Justin Quinn (Supervisor)