Comparison of modelling approaches for the bending behaviour of fibre‐reinforced thermoplastics in finite element forming analyses

Abstract

AbstractIn the forming of thermoplastic composite laminates, the temperature‐dependent bending behaviour plays a significant role, in addition to in‐plane tension, in‐plane shear and ply/ply as well as tool/ply friction. The bending properties are decoupled from the in‐plane properties. Classical beam theories are therefore not valid for laminates, as they significantly overestimate the bending stiffness, especially in the molten state. Various approaches to modelling the bending behaviour have been presented in the literature, which can be used to model the out‐of‐plane properties for simulation. With these approaches, a parameter optimisation based on experimental deflection curves is performed through cantilever beam tests. A comparative analysis is then carried out to evaluate the suitability of a temperature and direction dependent modelling of the bending behaviour, the influence of the in‐plane properties and the computation time.