Concrete subjected to projectile and fragment impacts: Modelling of crack softening and strain rate dependency in tension

This paper deals with modelling of plain concrete in tension. The aim is to improve the accuracy of the numerical analyses for projectile and fragment impacts on concrete. A bi-linear crack softening law and a strain rate-dependent law are implemented in the hydrocode AUTODYN. Parametric studies are made, and numerical analyses are compared with experiments conducted and with experiments found in the literature. The depth of penetration is mainly dependent on the compressive strength of the concrete. However, to correctly model spalling, cracking and scabbing in concrete, the tensile strength, fracture energy, and strain rate in tension are very important. It is shown that the accuracy of the results in the numerical analyses of concrete subjected to projectile and fragment impacts was improved, when using a bi-linear softening law and the modified strain rate dependency for tension.