Strain Rate Effect in the Mesoscopic Modeling of High-Strength Steel Fiber-Reinforced Concrete

Abstract

Abstract. The research, presented in this paper, aims to investigate the behavior of a High-Strength Steel Fiber-Reinforced Concrete (HSSFRC) mesoscopic nite element model at compressive high strain rates. In order to produce a three-dimensional meso-scale nite element model, a computer code is developed to randomly produce mesoscopic models of SFRC specimen. The specimen is assumed to be reinforced by 0.6 percent volume fraction of hooked steel bers (Dramix RC-65/35-BN) with random positions and orientations. Aggregates of the compound are assumed to have spherical shape and are produced according to Fuller grading curve. Based on the initial mesoscopic model, a nite element model is produced and used in an explicit dynamic simulation. The contribution of inertial con nement to the dynamic strength enhancement of concrete at high strain rates was investigated, and its e ective role was observed. Accordingly, de ning a Dynamic Increase Factor (DIF) for mortar matrix led to overestimation; nevertheless, the inertial con nement by itself could not justify the increment of specimen strength under the dynamic loading. Obtained results also show that steel bers have a negligible in uence on the strength, strength enhancement ratio (DIF), and post-peak behavior of the model at high strain rates.

Dynamic Constitutive Model Analysis of High Parameter Steel Fiber Reinforced Concrete

“…E d is the elastic modulus of initial stress-strain curve of concrete under dynamic condition, ε d0 is the dynamic damage limit strain [16], D d is the damage coefficient of concrete under dynamic state.…”