Data-based damage evolution analysis of chopped carbon fiber sheet molding compound composite

The study investigates the damage evolution mechanisms in chopped carbon fiber sheet molding compound (CF-SMC) composites subjected to uniaxial tensile loading through a data-driven approach integrating micro-X-ray computed tomography (μXCT) and multivariate correlation analysis. Initially, μXCT imaging provided comprehensive in-situ characterization of internal microstructural damage processes, identifying fiber orientation, fiber volume fraction, and loading conditions as critical variables influencing crack propagation. Subsequently, a quantitative damage evolution prediction model was developed. A data-based approach was employed to translate complex multi-variable nonlinear relationships into a single-variable analysis. The model introduces a Damage Evolution Index (DEI), effectively capturing the influence of identified critical factors on crack growth rate. Validation using independent tensile testing datasets confirmed the accuracy and generality of the proposed prediction framework, demonstrating its potential applicability in advanced structural health monitoring and damage prognosis for composites.