Bar finite element with bond-slip for R.C. seismic analysis

A finite element of reinforcing bar embedded in concrete is presented, which models the interaction between the reinforcing steel bar and the bond action exerted by the surrounding concrete over the bar surface. In developing the finite element approximation a flexibility approach is followed, where the steel stress field is discretized. The finite element accounts for material nonlinearities through the constitutive laws of steel and bond. A well tested flexibility-based iterative algorithm is adopted within the element to treat softening behavior induced by bond degradation. Comparisons with experimental results show excellent agreement