A plasticity-based dynamic constitutive model for ultra high toughness cementitious composites.

• A plasticity based constitutive model for ultra high toughness cementitious composites under projectile impact and blast loads is proposed. • Dynamic tensile and compressive properties are treated separately with continues transitions. • Advanced performances of the new model over existing models are proved by single element tests. • Material resistance and failures are well predicted under penetration and contact blast scenarios. Ultra high toughness cementitious composites (UHTCC) have a wide range of application prospects in various protective structures. At present, various concrete material models have been frequently used to simulate the mechanical response of such materials subjected to high-speed impact and explosive loads. However, none of these models can accurately describe the tensile ductility, strain rate effect, and shear expansion effect of UHTCC, which may lead to inaccurate numerical simulation results. In this study, a dynamic constitutive model of UHTCC was established, which comprehensively considered damage evolution, shear expansion, strain rate, strain hardening and strain softening of such materials. It was implemented into LS-DYNA software through a user-defined interface. Then comprehensive element tests were conducted and compared with the commonly used concrete models. Finally, a set of experimental tests of the UHTCC subjected to high-speed impact and contact blast loads were simulated. It was found that the numerical prediction results were in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]