Modelling of crack initiation in fibre-reinforced injection moulded parts

Abstract

This study addresses the effects of injection moulding weld lines and fibre orientation distributions on the mechanical properties of short fibre-reinforced thermoplastics (SFT). In this thesis, a literature review, as well as numerical simulation, is carried out. The literature review presents the fibre orientation models and micromechanical models used to predict the stiffness of anisotropic materials. While a parametric study is conducted to study the influence of process parameters on the flow-induced fibre orientation for injection moulded fibre composites. The study found that fibre orientation process parameters have a significant impact on fibre orientation. Moreover, the mechanical properties of an injection moulded part are examined by simulating it in Moldex3D. And the results were transferred to structural analysis software ABAQUS to establish a model which can predict crack initiation at weld lines under quasi-static loading. According to the findings, optimising processing parameters and fibre orientation using experiments and simulations can improve the outcome of a moulded part.