Mechanical behavior and damage evolution for concrete subjected to multiple impact loading

Abstract

In order to explore the dynamic mechanical properties and damage evolution for concrete under the repeated impact loading, the large-diameter (74 mm) Split Hopkinson Pressure Bar (SHPB) was used to conduct the dynamic compression test. The damage was calculated by the Weibull statistical damage model, and the stress-strain curves of concrete were analyzed to study the repeated impact loading effects on the damage of concrete. Meanwhile, the fracture process of the concrete was simulated with the finite element software (LS-DYNA) and Johnson Holmquist Concrete (*MAT_JOHNSON_HOLMQUIST_CONCRETE) constitutive model. The results showed that the dynamic elastic modulus and the peak stress of the specimens decreased with the increased number of repeated impacts, while the peak strain increased. The damage of concrete increased with the increased strain, and the damage increased sharply after the “inflection point”. In addition, the results obtained by finite element simulation agree with the experimental results.