Abstract: Understanding the influence of hole geometry on the elastoplastic behavior of fiber-reinforced composites is critical for designing lightweight, high-performance structural components. This study introduces an efficient framework that combines a simplified theory of small elastoplastic deformations for transversely isotropic media with the finite element method, enabling accurate prediction of stress and strain localization in perforated composites. The material is modeled as an elastoplastic continuum composed of stiff reinforcing fibers embedded in a softer matrix, capturing key anisotropic effects while avoiding costly multiscale simulations. A systematic parametric study of circular, elliptical, and crack-like holes reveals that hole geometry dramatically alters stress concentration patterns. In particular, when the ratio of the semi-axes of an elliptical hole falls below 0.2, maximum shear stresses localize near the lateral surfaces, creating a high risk for matrix–fiber separation and damage initiation. The findings provide quantitative design guidelines for optimizing hole shapes in reinforced composites and demonstrate a practical method to bridge the gap between idealized elastic models and computationally intensive full-scale elastoplastic simulations. This approach offers direct relevance for aerospace, automotive, and energy applications, where stress concentrators critically impact structural reliability.

Keywords: fiber, matrix, composite, deformation, effective mechanical parameters, hole, stress

Pages: 224-232