Mesoscopic numerical simulation of axial tensile specimen of concrete

In order to investigate the damage and failure mechanism of concrete under axial tension, the numerical model of axial tensile concrete specimen with random distributed aggregate and meso-phases nonhomogeneous material mechanical parameters was established by the ANSYS parametric design language. The evolution process from the micro-crack appearance to growth and the final fracture of the concrete specimen, as well as the stress-strain curve were obtained through the numerical analysis. According to the analyzed results, although uniform tension stress was loaded on the axial tensile specimen of concrete, the distribution of stress and strain in the specimen is non-uniform because of the random distribution of aggregates and the difference of the mechanical properties of meso-phase materials. There are three stages, i.e., dispersion stage, concentration stage and localization stage during the propagation process of crack. Aggregates form weak interface, one hand which results in concrete crack, in other hand, the existence of aggregates has obstruction to the development of concrete crack. In physical test, it is difficult to load on the accurate center of specimen, and there is deficiency on homogenization method of concrete on macro level, the numerical method proposed in this paper can solve these problems, and is advantageous in revealing the damage and failure mechanism of concrete.