Finite element analysis on the Meppen Slab Tests -modelling approach & first results

In this paper the modelling approach and some results of Finite Element (FE) analyses on the 4 th test of the second series of the Meppen Slab Tests using the explicit FE solver RADIOSS are described. The Meppen Slab Tests were performed in the 1970s and early 1980s to assess the safety of Concrete Containment Buildings of German nuclear power plants against the impact of aircrafts. The FE analyses that are subject to this article were carried out within the Benchmark Project "Improving the Robustness of Assessment Methodologies for Structures impacted by Missiles (IRIS)" of the Subgroup on Concrete of the Working Group on the Integrity and Ageing of Components and Structures (IAGE) of the Nuclear Energy Agency (NEA) of OECD. Lagrangian meshes are used for the missile and the concrete slab. Special emphasis is put on the constitutive models of the involved materials. A Drucker-Prager/Cap model is used to model the constitutive behaviour of the concrete. Isotropic elastic-plastic constitutive models with strain-rate dependencies are used for the missile and steel reinforcements of the concrete slab. Failure mode, crack pattern of the concrete slab and shape of the deformed missile of the Meppen-II-4 Test are resembled by the FE analyses. A shear cone is clearly induced in the model of the concrete slab and its dimensions agree well with the dimensions of the shear cone from the real test. The FE model clearly shows vibrations of the concrete slab, which is typical for flexural tests. The calculated residual centre deflection on the backside of the concrete slab and the calculated magnitude of the contact force between missile and concrete slab are in very good agreement with measured values. In summary, with today's explicit FE solvers it is possible to predict the global outcome of high impact problems like.