RVE-based simulation analysis of mechanical failure mechanisms in alumina fiber-reinforced aluminum matrix composites

Abstract

Continuous alumina fiber-reinforced aluminum matrix composites (Al2O3f/Al) were investigated using an RVE-based finite element framework to clarify mesoscopic failure mechanisms under tensile and bending loads. An RVE with 60 vol.% fibers in a periodic diagonal-square arrangement was constructed. Interfacial debonding was modeled by a zero-thickness cohesive zone model (CZM) with a bilinear traction–separation law. The aluminum matrix damage evolution was described by the Johnson–Cook model, and fiber fracture was predicted using a maximum-stress criterion implemented via a user-defined Fortran subroutine. The simulated tensile stress–strain curve agreed well with experimental results, especially in the elastic regime and near the peak load (ultimate tensile strength ∼1650–1670 MPa at strain ∼0.008–0.0082), supporting the reliability of the model for stiffness and strength prediction. The simulations indicated a consistent failure sequence of interface damage followed by matrix damage and final fiber fracture, highlighting the dominant role of interfacial integrity in load transfer. Under bending, fiber failure was governed by compression-driven damage on the compressive side. This approach provides quantitative support for interface design and performance assessment of Al2O3f/Al composites.