Simulation of Impact Tests With Hard, Soft and Liquid Filled Missiles on Reinforced Concrete Structures

Vital parts of nuclear facilities are commonly protected by reinforced concrete (rc-) structures. In order to assess the barrier effectiveness of these structures, different internal and external loads have to be considered. Among others, external missile impacts, for instance due to an airplane crash, are assumed to be relevant loading cases. In this context, impacts of nondeformable (“hard”), deformable (“soft”) as well as liquid filled (“wet”) missiles are considered. Major rc-target failure mechanisms are global bending, punching and perforation. This paper presents simulations with the computer program AUTODYN (ANSYS INC., 2010, ANSYS AUTODYN, Version 13.0 & Theory Manual) on intermediate- and large-scale impact experiments dealing with the aforementioned failure mechanisms. Missile velocities are in the range of 110 to 250 m/s. In particular, two different intermediate scale test series are considered. One test deals with predominant punching failure and perforation of a rc-slab (target) hit by a hard missile. Further, bending vibration of slabs impacted by soft missiles is analyzed, whereupon the influence of liquid infill on loading and target response is pointed out. Finally, a large scaled test with combined bending and punching failure of a rc-slab due to soft missile impact is considered. Results of numerical simulation and tests are compared. It is found, that the used concret material model developed by Riedel, Hiermaier, and Thoma (RHT) (Riedel, 2004, “Beton Unter Dynamischen Lasten: Meso-Und Makromechanische Modelle Und Ihre Parameter, Fraunhofer–Ernst-Mach-Institut, Freiburg/Br., ISBN 3-8167-6340-5) is suitable to reproduce the responses of rc-structures subjected to various kinds of impact conditions. Sensitivities of simulation results on modeling parameters are discussed.