Numerical simulation of a 1/6-scale concrete containment model

Prediction of the response of the Sandia National Laboratories 1/6-scale reinforced concrete containment model test was prepared by the Engineering Mechanics Program of Argonne National Laboratory. The two-dimensional code TEMP-STRESS and the three-dimensional NEPTUNE code was utilized in the present study to predict the global response of the structure, to identify global failure sites and their corresponding failure pressures, and to identify some local failure sites and their pressure levels. An axisymmetric model was studied with the program TEMP-STRESS and a three-dimensional circumferential segment model with the program NEPTUNE. These models are used to predict various failure mechanisms, such as hoop failure of the vessel at midheight following failure of a splice in this area and failure of a weld in the liner near the basemat due to excessive strains. In reality, simultaneous failure in more than one mechanism is unlikely since the onset of failure in any one mechanism will reduce the pressure and therefore reduce the stress on other possible sites of failure. The analytical approaches in TEMP-STRESS and NEPTUNE are similar. Both codes use explicit temporal integration for dynamic problems and dynamic relaxation for static problems. This enables the codes to be used for static as wellmore » as dynamic problems. The choice of the integration scheme was primarily dictated by the high nonlinear concrete behavior and the relative ease of accounting for nonlinearity in this type of algorithm. At each load step, equilibrium is obtained when a force and displacement criteria are satisfied. 7 refs., 4 figs.« less