Homogenization and localization of unidirectional fiber-reinforced composites with evolving damage by FVDAM and FEM approaches: A critical assessment

Abstract

The recently-developed finite-volume direct averaging micromechanics (FVDAM) with progressive damage simulation capability modeled using the cohesive zone model is critically and fully assessed vis-à-vis Abaqus, a widely-adopted commercial finite-element code with cohesive element for the first time. The evolving debonding along the fiber/matrix interface of a unidirectional metal matrix composite is simulated using comparable bilinear traction-displacement separation laws in the two computational approaches. Differences between the two approaches are highlighted, including shortcomings of the Abaqus-based finite-element analysis of evolving damage. These shortcomings include the need of optimizing the compressive stiffness of the interface in order to: avoid material interpenetration; predict correct homogenized response; prevent numerical instabilities. These problems are not present in our version of the finite-volume homogenization approach since the traction-separation relations in the affected normal direction are directly eliminated when the interface is under compression. Nonetheless, comparison of the homogenized response and localized stress fields generated by the finite-element and finite-volume techniques demonstrates good agreement between the two approaches provided that a suitable compression factor is chosen in Abaqus.