| The investigation reported herein consists of experimental and theoretical studies of low-cycle fatigue behavior of plain and fiber reinforced concrete. Almost one hundred 4-inch cube specimens have been tested proportionally under load control in biaxial cyclic compression with constant stress ratio of {dollar}sigmasb1/sigmasb2=1{dollar} and constant load amplitude. The variables studied were steel fiber volume (0, 0.25, 0.50, 0.75, 1.0%) and stress-to-strength ratio (0.85, 0.90, 0.95). Five specimens were tested for each data point. The attention was focused on stress-strain behavior characteristics, fatigue life, total energy absorption capacity, and total strain accumulation. The experimental results, presented in tabular and/or graphic formats, were analyzed and interpreted extensively.; Based on the work by Peng et al. (71, 72), an elastoplastic damage model was developed for plain and fiber reinforced concrete. It consists of elastic spring and dashpot-like block elements which were employed to establish the elastoplastic constitutive relations. A fourth-order damage effect tensor was introduced to simulate the unilateral effect and damage induced anisotropy. Damage evolution was assumed to be associated with the current stress state and past damage accumulation. The model is applicable to both monotonic and cyclic loading under any stress state. |
