Localization Analysis of Reinforced Concrete Members with Softening Behavior

This paper presents a method of analysis for evaluating the softening behavior of reinforced concrete (RC) members. To obtain mesh objective results, a nonlocal fiber element model is introduced. The resisting force of each section, in the nonlocal fiber element model, is calculated using a proposed differential hysteretic model, which is especially developed for modeling softening behavior under cyclic loading. The section hysteretic response is determined using microplane constitutive law for concrete and bilinear elastoplastic law for reinforcements. The calculated hysteretic behavior of sections is employed to scale the parameters of the differential hysteretic model. The proposed method is verified by the available experimental results. Close agreements between the numerical and experimental results are obtained. The method provides insight to the procedure of flexural localization. Also, due to computational efficiency of the method, it is possible to extend its use for analyzing RC frames with softening members.