Tension Stiffening Model for Numerical Analysis of RC Structures by Using Bond-Slip Relationship

In this paper, a tension stiffening model based on the bond-slip relationship is introduced and adopted in a finite multilayered shell element formulation for surface structure analysis. The tension stiffening effect evaluated at the meso-level is taken into account in the constitutive law of reinforcement at the macro level by defining a crack element at the Gauss point. The crack element is iteratively analyzed by means of a step-by-step integration, which allows application of any complicated bond laws. To define the crack element, a crack spacing model considers the crack formation grade. As a relevant factor in this tension stiffening concept, the reinforcement cracking stress may be evaluated by taking the fractile value of the concrete tensile strength. Through several simulations, the validity of the concept is systematically investigated under monotonic and cyclic loading. The analysis under cyclic loading shows the effect of the re-contact of the crack flanks. The numerical examples demonstrate the applicability of the applied reinforced concrete model with a tension stiffening effect.The author would like to acknowledge the precious advice of Professor Dr.-Ing. E.h. W.B. Krdtzig at RuhrUniversity Bochum in Germany through the whole process of this study. This research was supported by the Sustainable Building Research Center of Hanyang University (R11-2005-056)