ENGINEERING APPROACH TO CALIBRATE A CONCRETE MODEL FOR HIGH SPEED IMPACT APPLICATIONS

Abstract

This paper describes a study on the mechanical response of concrete under high-velocity impact. It encompasses both experiments and numerical simulations. The aim is to validate an approach for building a concrete numerical model sufficiently robust and accessible to be used for designing civil or defense infrastructures. A conventional concrete (35 MPa compressive strength) has been chosen to apply the method. Experimental tests are conducted to characterize the material in compression and to measure its residual strength during compaction. Impact tests of a kinetic energy projectile (KEP) with an ogive shape nose are also conducted at velocities ranging from 200 to 900 m/s to reproduce both subsonic and supersonic impact conditions. The effect of the concrete confinement is investigated by varying the thickness of a metal jacket surrounding the impacted specimen. Regarding the numerical model, a Holmquist–Johnson–Cook (HJC) for concrete has been calibrated from the measured data. Simulations of the impact perforation are conducted with the γ-SPH solver available in IMPETUS AFEA TM . The numerical model has been able to reproduce the main damage in the concrete during the projectile penetration. Good correlation in terms of deceleration profile during penetration is obtained with the experiment. Moreover, the model is robust enough to reproduce the effects of the confinement variation in the projectile residual velocity. This methodology could be applied to other types of concrete materials subjected to various loadings such as near-field blast for example.