The effect of stand-off distance on the failure of fully clamped circular mild steel plates subjected to blast loads

The effect of stand-off distance and charge mass on the response of fully clamped circular mild steel plates, of radius 53 mm, subjected to blast loads travelling along tubular structures is reported. The procedure consists of creating a blast load using plastic explosive mounted onto the end of mild steel tubes. The stand-off distance is varied, from 13 to 300 mm, using different tube lengths.The plate responses range from large inelastic deformation to complete tearing at the boundary. Different loading regimes are observed, depending on the stand-off distance between the explosive charge and the plate, and are classified according to the plate response. At stand-off distances less than the plate radius (13–40 mm), the blast load is considered to be focused (localized). For stand-off distances greater than the plate radius (100–300 mm), the loading is considered uniformly distributed over the entire plate area. Theoretical and empirical analyses are performed, to enable predictions of the mid-point deflection. Appropriate modifications are introduced to account for the effect of stand-off distance on plate deformation. The modified analyses show satisfactory correlation with experimental results.