Abstract：To explore the damage modes as well as the transitions between them for stiffened plates subjected to close-range air-blast loading produced by the explosion of missile warheads, finite element simulations were carried out to investigate the damage modes and the critical stand-off distances between different modes in the case of the explosion over the centre of the stiffened plates. The influences of the scaled distance and the dimensionless damage factor Df were analyzed. A damage mode map related to Df-0.5 and was obtained. The criteria of different damage modes was proposed. Meanwhile, equations were presented to determine the critical stand-off distances between different damage modes. Results show that, for a gvien charge and a stiffend plate, if the condition ( Df0.5)>0.0233m/kg1/3 is fulfilled, the stiffened plate will experience in sequence Mode I (large plastic deformation), Mode II (tensile tearing at the middle point of the long boundary) and Mode III (crevasse at the centre of the plate) as the stand-off distance reduces. Otherwise, if ( Df0.5)≤0.0233m/kg1/3, only Mode I and Mode III were successively underwent by the stiffened plate as the stand-off distance decreases.
2013, Vol. 32 
