Modelling dynamic failure of geometrical-similar concrete subjected to tension-compression loads: Effect of strain rate and lateral stress ratio

Concrete materials are widely acceptable to practical structural buildings exposed to not only uniaxial loads but also complicated stress states. Additionally, concrete structures under quasi -static loads may suffer from inevitable occasional dynamic loads. In this study, mesoscopic modelling on geometrical-similar concrete was conducted. Numerical experiments were per-formed under dynamic biaxial Tension-Compression loads with different strain rates (ranging from 10(-5) s(-1) to 1 s(-1)) and lateral stress ratios (ranging from-1.00 to 0). The effect of lateral stress ratio and strain rate on the mechanical damage behavior and size effect of geometrical -similar concrete was discussed. The numerical results indicate that the size effect on dynamic spindle compressive strength and dynamic lateral tensile strength are weakened with the increasing strain rate. However, the increasing lateral stress ratios bring different impacts on the size effect, namely enhancing the size effect on dynamic spindle compressive strength and weakening the size effect on dynamic lateral tensile strength. Moreover, considering the coupling effects between lateral stress ratio and strain rate, a dynamic Tension-Compression failure cri-terion for concrete was proposed. Finally, a static-dynamic universal size effect formula on the lateral tensile strength of concrete under dynamic Tension-Compression loading was established and verified.