Citation

Yankelevsky DZ. Int. J. Impact Eng. 2017; 106: 30-43.

Copyright

(Copyright © 2017, Elsevier Publishing)

DOI

10.1016/j.ijimpeng.2017.02.021

PMID

unavailable

Abstract

Penetration into concrete is a subject of much interest and importance that attracts researchers for many years. This paper aims at reviewing the major contributions to model the deep penetration of a rigid projectile that perpendicularly hits a concrete target with emphasis on concrete target resistance. With regard to the concrete target resistance there exist four major modeling families: empirical, semi-empirical, analytical and theoretically based computational models. The paper overviews representative models and shows what target resistance parameters are used in these models and discusses some inherent weaknesses. The paper mainly refers to the dependence of concrete target resistance on the material characteristics; the concrete unconfined strength clearly appears to be the major identifier of the target resistance in these models. In many expressions the penetration depth is inversely proportional to the square root of the unconfined strength. The paper debates with this formulation which correlates the target resistance with the unconfined compression strength through a smooth continuous function of the strength disregarding the effect of different concrete mix designs that produce the same unconfined strength. Our own experimental studies are described to prove that concrete targets of similar unconfined strength demonstrate different resistance and damage depending on the different concrete compositions. Attention is given to the comprehensive description of target resistance via the equation of state and the failure envelope; this material behavior presentation is common in computational models, and is also adopted, although in a very simplified form, in analytical models. However, it will be shown that these advanced models are also commonly identified through the unconfined strength, and therefore they poorly describe the specific characteristics of the material under discussion. There is a need to produce refined data for the equation of state and of the failure envelope that are related to the concrete mix characteristics. Recently a new wide scope testing program has been initiated at our laboratory to achieve that goal, and early results have already been produced.

Language: en

Keywords

Advanced material testing; Concrete penetration models; Equation of state; Material properties