A Combined Discrete and Continuum Fatigue Damage Characterization of a Hybrid Composite Flexbeam

Strength and life prediction of a nonlinear tapered hybrid composite flexbeam under combined axial tension and bending is a challenging problem due to the presence of a complex geometry, a hybrid composite material system with a combination of glass/epoxy and graphite/epoxy composites, and a variable thickness profile along the beam longitudinal direction. A hybrid approach based on the combination of discrete crack network (DCN) and continuum damage mechanics (CDM) is applied for fatigue damage prediction under pure bending and bending with axial loading. Abaqus solid shell elements (SC8R) with composite section were used to capture the stress distribution and its concentration at the ply drop location. A hybrid modeling strategy is developed based on Abaqus solid shell elements (SC8R) with a user-defined material model for non-critical damage zones, user-defined phantom paired solid elements for critical damage zones, and Abaqus elements for non-damaged regions. A comparative study is performed for a representative flexbeam with and without the application of an axial force.