This study explores the failure processes of bundles of plastic fibers within plastic fiber-reinforced composite materials (PFRCs), based on fiber bundle models (FBMs) that incorporate elastic-plastic behavior and statistical variations in yielding and breaking thresholds.

The investigation includes analytical derivation and numerical simulations to model the macroscopic and microscopic failure mechanisms of plastic fiber bundles. Results indicate a transition from gradual to abrupt failure as the plastic coefficient decreases, with catastrophic failure occurring when the weakest fiber initiates collapse. Failure proceeds through avalanches, characterized by power-law size distributions, whose statistical properties depend on the plastic coefficient and stress field heterogeneity. Finite-size scaling analysis reveals critical exponents and identifies the transition as analogous to continuous phase transitions.

The study provides significant insights into the fracture dynamics of PFRCs, offering a basis for predicting material behavior under mechanical loads and improving the reliability of composite materials in engineering applications.