Modelling of reinforced materials by a subcycling algorithm

The high nonlinearity associated to the interface and constituents in reinforced materials -e.g. reinforced concrete- has motivated the development of this subcycling algorithm. The interface modelling and the complex material model used to represent the continuum implies a small critical time step when solving a spatial discretised finite element mesh with an explicit time integrator conditionally stable. Making two subcycles -one for the continuum and the other one for the reinforcement- the smallest critical time step does not rule the other sub cycle. The interface is modeled by transmission conditions including empirically-based bond stress-slip relationship. A set of pullout tests of reinforcing bar embedded in a surrounding continuum to demonstrate the efficiency of the scheme is presented and, then, validated against experimental results from the literature. The attractiveness of this scheme lies in the computational efficiency implied by running reinforcement and continuum at two different velocities of execution and solve the problem of nonlinearity created in the interface of very distinct materials.