Modeling of concrete under high strain rate conditions using nonlinear finite element method

Abstract

In this study, a comprehensive experimental and numerical study was undertaken to model concrete under high strain rate conditions. Concrete cylinder specimens, all obtained from the same batch, were tested both under ststic and high strainrate conditions. 15 eylinder specimens were tested under 3.55x10-5, 3.23x10-4, 2.97x10-3 1/s strain rates, whereas three identical specimens were tested using a Split Hopkinson Pressure Bar SHPB) tes setup under 235, 245, 260 1/s strain rates. Used SHPB setup was modified to include quartz crystal stress developed in the specimens werw directly obtained, eliminating common isssues regarding stress readings in a conventional setup. Stress-strain behavior and other material parameters that would be necessary for numerical modeling were obtained under various strain rates. Test samples were modeled using an explicit finite element program LS-DYNA, using Holmquist-Johnson-Cook model with experimentally obtained model parameters. To verify the obtained parameters further, drop tower test on concrete plates were also performed and modeled. Numerical modeling of both SHPB samples and concrete plates were successful in capturing the observed behavior. The study also provided the literature with a reliable test data with complete parameters that can be used for further studies in the area.