Numerical analysis of impactor models penetration into a concrete barrier taking into account the detachable pallet influence

Abstract

Numerical simulation within the framework of two-dimensional axisymmetric problem of continuum mechanics made it possible to analyze penetration into a semi-infinite concrete barrier with impactor models having diameter of 14 and 18 mm and initial speed of 1200 m/s. Influence of the detachable pallet used to accelerate the models in the ballistic installation barrel was both taken into account and not taken into account. Within the penetration process, the impactor models and the pallets were considered to be the absolutely rigid non-deformable bodies. The impactor model head was conical with or without a nasal blunt. Positive effect of blunting the head was established on the dynamics of penetration of the impactor models, which resulted in the increase in their penetration depth and the decrease in the maximum overload caused by the cavitation effect manifestation with the presence of blunting. When simulating penetration of the impactor models installed in a detachable pallet, a decrease was registered in the penetration depth by slightly more than 10% with an increase in the maximum overload compared to the case of penetration with a missing pallet. The negative influence reason of the pallet on the impactor models penetration was revealed. It consists in an increase in the shear stresses acting on the model contact surfaces with the adjacent layer of the destroyed concrete caused by compression of this layer by the pallet, until the pallet is completely separated from the impactor model.