Theoretical analysis of dynamic spherical cavity expansion in reinforced concretes

This paper aims to establish a model that considers the penetration resistance caused by the constraint effects of steel reinforcements on concrete. Firstly, based on the experiment phenomena that reinforcements increase the toughness and tensile strength of concretes, the fitting relational expression between toughness of reinforced concrete and ratio of reinforcement was used to improve the Griffith yield criterion for reinforced concrete. Then, the dynamic spherical cavity expansion analysis was developed using the improved Griffith yield criterion as constitutive model and the dilation equation as equation of state, and the response regions were consisted of six distinct zones: cavity, compaction zone, dilation zone, radially cracked zone, elastic zone and undisturbed zone. This dynamic analysis considered the compression and dilation of concretes at the same time and was applicable to the penetration problem of reinforced concrete target. At last, based on the theoretical model of this paper, the experiments of projectiles with different weights penetrating into reinforced concrete targets with different reinforcement ratios were calculated using penetration analysis method of rigid projectiles. The comparison results showed that the theoretical analysis model of this paper can be used to predict the depth of penetration and other physical parameters such as velocity and deceleration with certain rationality.