PARTICLE BOND-DEGRADATION MODEL FOR CUMULATIVE DAMAGE ANALYSIS OF CONCRETE UNDER CYCLIC LOADING

Numerical tests of concrete subjected to cyclic loading were preformed using particle flow code software, and the simulation results show that: the distribution of local friction energy reflects the potential area of damage; the cumulative friction energy has a linear relationship with the number of loading cycles; the cumulative rate of friction energy is sensitive to the load level. Based on the correlation between friction energy and fatigue damage, a bond-degradation model based on cumulative friction energy is proposed, and the relationship between model parameters and fatigue life is analyzed. The simulation results of the fatigue test show that: the proposed model can simulate the fatigue life of concrete under cyclic loading, as well as the fatigue damage behavior such as deformation evolution, stiffness degradation and crack evolution. The model can be used to analyze the cumulative characteristics of concrete fatigue damage under complex load conditions.