The penetration and perforation of concrete targets: A 3D meso-mechanical modelling

A numerical study is conducted herein on the penetration and perforation of concrete targets by a 3D meso-mechanical model which considers concrete as a three-phase material containing mortar matrix, aggregates and ITZ (interfacial transition zone) layers. In order to model the irregular shapes of aggregates more realis-tically, a new algorithm is developed. Furthermore, the influences of aggregate volume fraction on projectile residual velocities, target crack patterns and crater sizes are examined in the case of perforation of finite reinforced concrete (RC) slabs. The numerical results obtained from the 3D meso-mechanical model and the ho-mogeneous model are compared with available experimental data. It transpires that the 3D meso-mechanical model predictions are in good agreement with the test results; that the present meso-mechanical model predicts better than homogenous model in terms of deceleration-time history, impact crater diameter and crack pattern even though these two models produce similar results for penetration depth, residual velocities and scabbing crater diameter. It also transpires that for given mortar and aggregate, increasing aggregate fraction will improve the ballistic performance of the concrete slab, especially for low impact velocities; that for a given macroscopic unconfined compressive strength, the influence of aggregate volume fraction is negligible.