Numerical simulation of cyclic bond-slip behavior

In the present paper the pull-out of deformed steel bar embedded in a concrete cylinder and pulled out by monotonic and cyclic loading is analyzed and discussed. The analysis is carried out by the use of axisymmetric finite elements and general microplane model for concrete. Current version of the model was not able to predict damage in shear due to cycling loading correctly. Therefore, the model is further improved and extended in a more general form. In the present numerical case study, instead of the classical interface element approach, a more general approach is used in which the geometry of the ribs of the deformed steel bar are exactly modeled. In the present numerical case study, the pull-out failure mechanism is analyzed and compared with experimental observations. The comparison indicate qualitatively good agreement. Predicted failure load is in good agreement with experimental results, however, calculated displacement are much smaller than measured in tests . The present approach is able to correctly predict the monotonic as well as cyclic behavior including friction and degradation of pull-out resistance caused by previous damage.