Large-strain 3D-analysis of fibre-reinforced composites using rebar elements: hyperelastic formulations for cords (Q1315897)

The well-known finite element representation of reinforcing bars by means of overlay (``rebar'') elements is recast in the context of finite strain analyses of cord-reinforced composite materials. The variational formulation including the linearized forms is presented on the basis of hyperelasticity. Three material laws including two variants of the neo- Hookean model and the quadratic logarithmic model are investigated. An explicit formulation for uniaxial stress states is given for neo-Hookean model. A comparative evaluation with regards to computational efficiency and physical plausibility shows that the logarithmic model is optimally suited for this class of problems and for moderately large strains.