A study of penetration of concrete by high velocity projectiles.

摘要

A combined experimental and analytical study of penetration of concrete by high velocity projectiles is presented. The conducted literature review offers a comprehensive historic survey of the accomplishments in the field of high velocity penetration mechanics, including an introductory discussion of major current research topics, and the employed experimental and analytical methods.; In the course of the experimental studies, spherical-nose copper and tantalum rods are gun lunched against concrete and reinforced concrete targets with velocities ranging from 1.5km/s to 1.9km/s. Targets are instrumented with a sequence of break gages which provide valuable data for characterizing the penetration process. Target hole profiles and projectile residual masses are measured and reported.; Analysis of the penetration performance of projectiles is conducted within the framework of the modified hydrodynamic theory of penetration. Based on the results of these calculations, the penetration efficiencies of copper and tantalum projectiles are compared for different values of impact velocities.; Three-dimensional axisymmetric calculations are conducted with the CALE (Arbitrary Lagrangian Eulerian) code. The computational work concentrates on a study of the capability of various concrete constitutive models to adequately represent the response of concrete to the high velocity penetration. All constitutive models studied account for the compressibility of concrete and employ either solid or porous equation of state models. The influence of these models on the penetration calculations is studied and presented.; The size of the plastic zone in front of the penetrator resulting from the analysis is compared with the experimental data (from the break gages). Comparison between the calculations and the experimental data shows that the porous equation of state model is more realistic in representing the elastic-plastic deformation in concrete. Effects of the initial porosity of concrete on penetration calculations are also studied and discussed.; Penetration prediction capability of various yield strength models is examined through comparison between the calculated hole profiles and the experimental data. In the case of the constant strength model, the calculated hole profiles are found to be rather insensitive to the value of von Mises yield strength and all significantly disagree with the experiments. The pressure dependent yield model is the only one that resulted in hole profiles that agreed with the experiments.