Implementation of a plasticity bond model for reinforced concrete

This study examines numerical integration schemes for incremental, elastoplastic interface characterizations. The motivating problem is modeling bond of reinforcing bars to concrete in finite element analyses. Five first order accurate numerical integration schemes are examined. Four algorithms use backward Euler integration, but the iterative methods for solving the resulting nonlinear systems of equations (i.e., the plastic correctors) differ. A proposed algorithm minimizes the number of nonlinear equations that are solved numerically; for the bond model usually only one nonlinear equation is solved numerically. The algorithm is comparatively robust with respect to local convergence for arbitrary interface displacements.