Dynamic tensile behaviors and crack propagation in fiber-reinforced cementitious composites: Experimental investigation and Peridynamic simulation

Abstract

Fiber-Reinforced Cementitious Composites (FRCC) have gained significant attention in engineering applications due to their superior mechanical properties and toughness, particularly under high strain rate conditions. This study performed dynamic tensile tests on FRCC at high strain rates (35-110 s⁻¹) using a Split Hopkinson Tensile Bar (SHTB) apparatus. Additionally, a novel Peridynamic (PD) model was developed for the SHTB and FRCC system, leveraging the advanced capabilities of the emerging PD theory. The study compared and analyzed dynamic tensile strength, ultimate tensile strain, strain rate effects, failure modes, and crack development in FRCC with different fiber ratios at various high strain rates, using both experimental data and PD simulations. The results show that the PD-SHTB-FRCC dynamic model developed in this study exhibits high consistency between numerical simulations and experimental findings, effectively capturing the processes of crack initiation, propagation, and complete failure in FRCC specimens. The dynamic tensile properties of FRCC improve significantly with increased strain rates, with polyethylene (PE) fibers providing superior reinforcement compared to steel fibers. Notably, the dynamic tensile strength, peak tensile stress, and ultimate tensile strain of FRCC increase significantly with rising strain rates, with specimens containing higher PE fiber content showing a more pronounced enhancement effect. For strain rates between 42.6 s⁻¹ and 76.1 s⁻¹, considering dynamic tensile strength, ultimate tensile strain, and peak tensile stress, the optimal combination for resisting dynamic tensile loads was 1.5% PE fibers and 0.5% steel fibers. At a strain rate of 99.8 s⁻¹, a 2% PE fiber ratio alone provided the best performance.