Transactions, SMiRT-22 San Francisco, California, USA - August 18-23, 2013 Division V ANALYSIS OF PUNCHING OF A REINFORCED CONCRETE SLAB WITHIN IRIS_2012 Javier Rodríguez 1 , Joaquín Martí 2 , Francisco Martínez 3 , Christian Schneeberger 4 , and Rainer Zinn 5 1 Technical Director, Principia, Madrid, Spain (javier.rodriguez@principia.es) 2 Director, Principia, Madrid, Spain 3 President, Principia, Madrid, Spain 4 Project Manager, Swiss Federal Nuclear Safety Inspectorate ENSI, Brugg, Switzerland 5 Partner, Stangenberg und Partner Ingenieur, Bochum, Germany ABSTRACT As part of the IRIS_2012 international benchmark, simulations were conducted to analyse impacts on reinforced concrete slabs by both rigid and deformable missiles. The analytical results were compared with physical tests conducted by the Technical Research Center VTT of Finland. In the impact discussed here, a rigid missile perforates the concrete slab. The missile is a thick steel tube filled with concrete with a total mass of 47.4 kg and strikes the target at 136 m/s. The target is a 250 mm thick, reinforced concrete slab that spans 2 m by 2 m and is held in a rigid supporting frame. Characterisation tests were provided for calibration of the parameters of the concrete models selected by the participants. Having reproduced those tests, the authors developed models for the slab and the missile. A damaged plasticity model was used for the concrete and the rebars were explicitly represented. The results obtained were very satisfactory in respect of the damage patterns caused in the concrete and the reinforcement; also, the calculated and measured values of the energy spent by the missile in perforating the slab differed by only 4%. INTRODUCTION Numerical simulation is used here to model the effects of missile impacts on reinforced concrete slabs. The need to analyse this situation arises in many fields, but constitutes a specific requirement imposed on nuclear facilities. In these impacts the missiles are conveniently classified into rigid and deformable, depending on their deformability in comparison with that of the target: a turbine rotor sector can be considered an example of the former, while an aircraft crash is a typical instance of the latter. The ability to simulate this type of problems is evaluated here by comparing the numerical results obtained in calculations with the observations produced in physical tests. The reported activities were carried out in the context of an international benchmark exercise named IRIS_2012, organised by the OECD/NEA/CSNI Nuclear Energy Agency to continue the work on IRIS_2010 (IRSN, 2011) with the general object of improving the safety of nuclear facilities and, more specifically, demonstrating the capabilities of current finite element techniques to reproduce the events triggered by those impacts (CSNI, 2012). The impact tests performed, which included both rigid and deformable missiles, were conducted at the Technical Research Center of Finland (VTT, 2010). A number of characterisation tests (such as uniaxial compression tests, Brazilian tests, and triaxial compression tests at various confining pressures) were also provided in order to describe the behaviour of the concrete and to allow determining the parameters of the constitutive models selected by the benchmark participants (IRSN, 2012). The rest of the paper describes the approach followed by the authors for modelling the impact tests and developing their contribution to the international benchmark. Although both rigid and