Modelling of nonlinear and dual-modulus characteristics and macro-orthogonal cutting simulation of unidirectional Carbon/Carbon composites

Owing to their excellent high-temperature resistance, Carbon/Carbon (C/C) composites have broad application prospects in the aerospace and nuclear thermostructure fields. However, their anisotropic nature makes it difficult to guarantee their surface quality during cutting. Therefore, a detailed understanding of the cutting process is required. This study adopts a macro-orthogonal cutting model of unidirectional C/C (UD-C/C) composites to investigate their cutting forces and cutting defects using the finite element method. First, the nonlinear stress–strain relationship of the UD-C/C composites is determined by considering the fibre orientations in tension, compression, and shear experiments. Second, based on the Jones–Nelson theory, an improved constitutive model that accounts for different moduli in tension and compression is established through a weighted compliance matrix (WCM). Third, a macro-mechanical finite element (FE) model of the orthogonal cutting of the UD-C/C composites is developed based on the Jones–Nelson theory and Hashin–Chang failure criteria. The simulated cutting forces show good agreement with the experimental results for different fibre orientations (0°, 45°, and 90°).