The Effect of Span Length on Damage Effectiveness Subjected to Massive Ordnance Penetrator

The MOP (Massive Ordnance Penetrator) is non-nuclear earth penetrator weapon which has the best damage effectiveness now. The targets of MOP will be deeply underground headquarters and hard deeply buried targets. It has been simulated by using LS-DYNA finite-element software to analyze damage effectiveness of MOP, especially the relation of minimal depth of the defense cover. and span length, which MOP attacks underground protective works under different span length. In the simulation, shotcrete layers, anchor-hold rocks and loose rocks are taken into account. The calculating results reveal that minimal depth of the defense cover growth slowing down along with the span length increasing when span length more than certain distance, which accord with the result from experiential formula.