Large deformation behavior of <scp>EP</scp>/<scp>HGM</scp> composite and constitutive model considering microstructure evolution

Abstract Hollow glass microspheres (HGM), as particle fillers in epoxy resin (EP), can reduce the mass density of the material and improve the yield strength. However, it remains challenging to evaluate the contribution of filler volume fraction to the mechanical properties of EP/HGM composites, especially in terms of strain‐softening and strain‐hardening mechanisms under large deformation conditions. In this work, the effects of HGM content on yield strength, elastic modulus, strain softening, and strain hardening of EP/HGM composites were investigated, and the relationship between microstructure evolution and mechanical parameters was analyzed. A large deformation constitutive model based on the Boyce‐Parks‐Argon(BPA) model was established, taking into account the effects of volume fraction and strain rate. The model is implemented in ABAQUS in the form of a VUMAT subroutine, and its reliability is verified. The results provide a theoretical foundation for further optimization of HGM‐reinforced composite design and contribute to the development of performance prediction methods for engineering applications. Highlights Investigated the mechanical properties and large deformation behavior of EP/HGM. Analyzed the impact of brittle particle incorporation on resin matrix damage. Developed a mechanical model for EP/HGM composites considering HGM content. The numerical model was successfully implemented in ABAQUS using the VUMAT.