Characterisation of Armour Properties for the Prediction of Rupture in Localised Blast Loading

Abstract

Material characterisation and numerical blast testing of four steels was performed to identify the key mechanical properties dictating their rupture threshold under localised blast loading. Tensile testing of cylindrical and notched samples was performed and the Johnson-Cook (J-C) strength and fracture parameters were calculated. Accounting for the change in stress triaxiality during the testing provided greater accuracy in replicating the tensile test results. A numerical modelling evaluation of each material under localised blast loading showed that the highest strength, lowest ductility steel provided the highest resistance to both deformation and rupture. The energy absorption to fracture in a notched tensile test was shown to correlate with the blast threshold of the steels. The material blast rupture threshold was also found to correlate well with the flow stress at fracture calculated directly from the J-C material model.