Abstract
A mesoscale model for fibre kinking onset and growth in a three-dimensional framework is developed and validated against experimental results obtained in-house as well as from the literature. The model formulation is based on fibre kinking theory i.e. the initially misaligned fibres rotate due to compressive loading and nonlinear shear behaviour. Furthermore, the physically-based response is computed in a novel and efficient way using finite deformation theory.The model validation starts by correlating the numerical results against compression tests of specimens with a known misalignment. The results show good agreement of stiffness and strength for two specimens with low and high misalignment. Fibre kinking growth is validated by simulating the crushing of a flat coupon with the fibres oriented to the load direction. The numerical results show very good agreement with experiments in terms of crash morphology and load response.
Highlights
In the last decade, stricter emission regulations were imposed in the automotive industry forcing them to reduce emissions
Crash-worthiness is crucial to car design, but when it comes to design of crash parts in composites, there is a lack of reliable Finite Element (FE) models, especially for the longitudinal crushing
This degradation eases the rotation of the fibres in a positive feedback process, which eventually leads to kink-band formation
Summary
Stricter emission regulations were imposed in the automotive industry forcing them to reduce emissions. The failure mechanism that can absorb the most energy during crash is kink-band formation [2], which is predominant for longitudinal compression loading [3]. Non-perfectly straight fibres rotating under an applied compressive load induce a degradation of the matrix stiffness This degradation eases the rotation of the fibres in a positive feedback process, which eventually leads to kink-band formation. The initial misalignment does not influence the stiffness and more importantly, the severity of the load drop has no correlation with the initial fibre misalignment These advanced features can usually be captured only by computationally expensive micro-mechanical models [28]. Due to the high efficiency, robustness and accuracy of the present model, this work is a major contribution towards simulation of kinking initiation and growth in composite structures
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
