Experimental response of high strength steels to localised blast loading

Modern high-strength and armour grade steels have developed continually increasing strength and fracture toughness, but there have been limited experimental investigations into their response to localised blast response. In this work, the response of four modern steels to localised blast loading is experimentally investigated. The deformation and rupture threshold is comprehensively characterised and a detailed fractographic investigation is conducted into the initiation and progression of rupture failure modes. It was found that for the current experimental setup, higher strength steels can outperform more ductile steels, and that steel with a tailored microstructure had a higher rupture threshold than three modern armour steels. All steels studied herein initiate rupture via ductile shear fracture, as opposed to tensile tearing which is common in lower-strength steels. Results showed that the deformation resistance cannot be predicted precisely using only yield strength, and only by considering strain hardening can the deflection response be more accurately predicted. A new non-dimensional impulse correction parameter was also developed that captures the effect of charge stand-off on the target plate deformation and rupture performance. The results demonstrate the suitability of high-strength steels for blast applications, and have application to the design and analysis of safer armour systems for blast protection.