Micro‐Damage Behaviors and Performance Prediction of Fiber‐Reinforced Composites With Different Curvatures Under Multiaxial Loads

ABSTRACT This study uses a progressive damage method to model composites with curved fibers, where micro‐stress responses and damage behaviors under various loads were comprehensively analyzed and a corresponding property prediction model was established. Simulation results were validated against literature and theoretical data, confirming their accuracy. Results show that the fiber curvature causes uneven stress distribution and degrades longitudinal properties while enhancing transverse/shear capabilities. Unlike straight‐fiber composites (which almost fail immediately upon large loads), curved fibers prolong damage propagation under transverse/shear loads. Under Y‐axis compression, curved fibers exhibit 24.3% and 27.6% higher displacement at initial damage and failure than straight fibers, respectively. The initial damage initiates at stress‐concentrated interfaces and gradually propagates to adjacent matrices/fibers. Curved‐fiber composites exhibit four fracture modes, among which Pattern A (fiber/matrix rupture + interface debonding) and Pattern D (matrix cracking + interface debonding) are most common. This method aids experimental micro‐damage analysis and micro‐property prediction of irregular fibers, which can provide parameters for multi‐scale simulations.