ANALYSIS OF PENETRATION RESISTANCE OF CONCRETE

A combined numerical and analytical study of penetration of concrete b y high-velocity (similar to 1.8 km/s) projectiles has been conducted i n order to study the effects of concrete's constitutive modeling on pe netration calculations. The results of the analysis are compared with the available experimental data. All constitutive models studied accou nted for the compressibility of concrete. The plastic yield condition was modeled with the von Mises yielding criterion using (1) the consta nt yield-strength mode; and (2) the pressure-dependent yield-strength model. Regardless of the value of the yield strength, application of a constant yield strength model is shown to result in nearly identical hole profiles that, in all cases, were significantly larger than those obtained through experimentation. Crater profiles calculated with the pressure-dependent yield model showed good agreement with the availab le experimental data, attributed to the increased target resistance to penetration. In addition, a detailed analysis of the flow field along the central streamline shows that the increase in the target's resist ance to penetration is also responsible for the growth in the time rat e of the projectile erosion.