Influence of charge backing on the response of blast loaded plates

This study focuses on characterizing the transient deformation of test plates which have been exposed to air blasts arising from air-backed and metal-backed explosive detonations. Four charge masses are considered, namely 10g, 15g, 20g and 25g masses of PE4 plastic explosive which were moulded into cylindrical charges of a constant 38mm diameter. The transient deformation of the test plates was captured using high speed Digital Image Correlation (DIC), which utilized two high speed cameras to record the experiments. The experimental plates exhibited plastic deformation with no tearing. The impulse imparted to the test plates increased fivefold when the charge was metal-backed. The permanent deflections from the metal-backed detonations were larger than for air, but not to the same degree as the impulse increase.