Experimental and finite-element investigation of hybrid carbon/kevlar fiber-reinforced concrete under high-strain-rate impact

Abstract

Concrete is inherently a brittle material due to its low tensile strength; as a result, it is prone to cracking or spalling under external loads. Previous studies have demonstrated that the incorporation of fibers into concrete can significantly enhance its tensile strength and improve its overall mechanical performance. This study investigates the dynamic mechanical behavior and failure mechanisms of hybrid carbon/Kevlar fiber-reinforced concrete (HCKFRC) under high-strain-rate loading using the split Hopkinson pressure bar (SHPB) test. The constitutive parameters of HCKFRC were determined through dynamic stress-strain relationships at different strain rates using the Johnson-Holmquist Concrete (JHC) model. LS-DYNA finite-element software was employed to simulate SHPB tests at varying impact velocities, the simulation results were compared with the experimental results. The x-directional strain history and the failure strength of the specimens under different impact velocities of the SHPB test, closely aligning with finite-element simulation results. Additionally, high-speed camera images of the specimen captured during the SHPB test facilitated the calibration of the erosion damage parameter in LS-DYNA. These findings demonstrate that, with appropriate constitutive model parameters obtained from the SHPB test, finite element simulations can effectively capture the failure progression observed in HCKFRC specimens under high-strain-rate loading.