A consistent formulation based on continuum mechanics for modelling strain softening in composite materials

To meet damage tolerance requirements in the aerospace industry, structural designers have increasingly adopted predictive numerical tools to model damage onset and evolution over the years. Composite material structures modelling, for example, presents a direct relation between model fidelity and computational cost, potentially leading to greater design iterations and costs. Continuum Damage Mechanics (CDM) benefits from the smeared cracking approach and displays the potential of high fidelity associated with efficient modelling. Conventional CDM models were initially developed under assumptions that may lead to inconsistencies at large deformation analysis. This work presents a brief review on the fundamentals of progressive damage formulations for intralaminar damage and proposes a novel consistent methodology. Analytical results were generated for an elementary level validation for both current and proposed methodologies. These models were implemented as user material models in Abaqus/Explicit and dependency on the element size discussed. A coupon level validation was conducted for each formulation, where the same dependency was noted allowing for conclusions to be drawn.