Simulation of standoff vertical-mortar fragment impact momentum on round targets

The probability distribution of the fragment strike location on round targets within the scope of the expanding cylindrical metal case of a mortar at the center of a vertical arena test is formulated. Recognizing the axi-symmetric configuration, the description of the strike location in Cartesian coordinates is transformed into local polar coordinates. The theoretical distribution is experimentally verified approximately and the intervening parameters are identified. The number of fragments ejected upon case disintegration is estimated using the well-known Mott's model. The distribution of the fragment weight was identified in a previous investigation as Weibull with specific parameters according to the fragment category: either finger or chunk. The impact momentum for the fragment rain upon striking the target is then simulated. An example of application illustrates the practical formulation of probabilistic statements concerning the vulnerability assessment of a set of round targets surrounding a central cylindrical mortar in a vertical arena test arrangement.