NONLINEAR ANALYSIS OF CONCRETE CONTAINMENT STRUCTURE UNDER SEISMIC EXCITATION

Abstract

Nuclear containment structure are very important as these check the radiation in case of an accident. The containment structure may be subjected to accidental loading, including seismic loading, which lead to geometrical as well as material non-linearities of reinforced concrete. The present work encompasses the 3D nonlinear analysis of concrete containment structures under various acceleration time histories of Koyna and El-Centro Earthquake. In this study, the classical and numerical finite element procedures for the solutions is employed. The reinforced concrete is-represented by elasto visco-plastic model and nonlinear strain rate sensitive behaviour for its 3D behaviour, to simulate its transient dynamic behaviour and material characteristics such as the cracking, tension stiffening, shear transfer across the crack. The necessary software AIRC3D modify to NCS3D and pre and post processors MESH3D for the analysis is used in UNIX environment on various computing machines to study the response of test and actual problems of containment structures under various earthquakes to validate the results with available experimental/ numerical results. It can be concluded from numerical analysis that computer program and material model employed is able to predict the nonlinear behaviour of three dimensional reinforced concrete structure under various earthquake loadings. The actual contain-ment structure which is analysed is found to be safe under Koyna and El-Centro earthquakes.