Modelling progressive failure of 3D-printed continuous carbon fibre-reinforced composites: strain rate and fibre path effects

Additive manufacturing of continuous carbon fibre-reinforced composites (CCFRCs) has gained increasing attention and adoption in high-performance applications, including lightweight automotive structures and personalised medical implants. However, complex curved fibre paths often cause spatial variations in fibre volume fractions and mechanical properties owing to the inherent anisotropy of the material. These inconsistencies present significant challenges for accurate modelling, particularly under dynamic loading conditions. In this study, we introduce a strain rate- and fibre path-dependent progressive failure (PDPF) method for modelling and analysing the mechanical response and damage evolution of 3D-printed CCFRCs. The model is developed by explicitly representing the fibre paths and assigning orthotropic material properties, while a user-defined material subroutine (VUMAT) is implemented in Abaqus/Explicit to incorporate the strain rate effects. High-speed tensile tests are conducted at four strain rates, 10⁻² s⁻¹, 1 s⁻¹, 10 s⁻¹, and 100 s⁻¹, to validate and calibrate the proposed model. The results show that the PDPF model is very effective for predicting the failure responses, and more importantly, it can be concluded that the fibre paths must be included in modelling the 3D-printed CCFRCs with inhomogeneous fibre distributions.