Rate-dependent Endochronic Damage Constitutive Model For Large Aggregate Concrete

Nowadays, most of the mass hydraulic structure are adopte the large concrete as a material, and during the period of service structures are working under dynamic loads, such as seismic load, wind load. But study on the behavior of concrete under both influences of stain rate and large aggregate is less, a lot of numerical analysis only considered strain rate effect, or large aggregate factors.In order to describe the mechanics characteristics of mass concrete under dynamic loads, based on the theory of endochronic and damage mechanics, the effect of strain rate and aggregate size on the damage variable of concrete is analyzed. An endochronic damage constitutive model of large aggregate concrete is proposed. The proposed model is used to analyze the multiple dynamic stress-strain curves and compare with experimental data. The results are in good agreement with the experimental data, and it can be used as the base for dynamic properties research of large aggregate concrete.Finally, nonlinear seismic responses of an arch dam are analyzed with this model and the model of endochronic and damage mechanics with normal concrete. The results is shown that the effect of strain rate and aggregate size on the strength and stiffness of concrete structures is remarkable.