Multiscale Model for Damage Analysis in Fiber-Reinforced Composites with Interfacial Debonding

This paper presents an adaptive multilevel computational model for the multiscale analysis of composite structures with damage due to fiber/matrix interfacial debonding. The method combines continuum damage modeling with displacement based FEM with a microstructurally explicit modeling of interfacial debonding by the Voronoi cell FEM (VCFEM). Three computational levels of hierarchy with different resolutions are introduced to reduce modeling and discretization errors due to an inappropriate resolution. They are (a) level-0 of a pure macroscopic analysis, for which a continuum damage mechanics (CDM) model is developed from homogenization of micromechanical variables that evolve with interfacial debonding; (b) level-1 of a coupled macroscopic-microscopic modeling to implement adequate criteria for switching from macroscopic analyses to pure microscopic analyses; and (c) level-2 regions of a pure microscopic modeling with explicit interfacial debonding. The CDM model for a level-0 analysis is constructed from rigorous VCFEM-based micromechanical analysis of the representative volume element (RVE) followed by homogenization. A numerical example of a composite laminate with localized loading is solved to demonstrate the limitations of CDM models and to demonstrate the effectiveness of the multiscale approach in predicting failure due to interfacial debonding.