Elastic-plastic seismic response analyses of structures supporting steam generators

Abstract

Three dimensional elastic-plastic seismic response analysis of structures supporting steam generators is carried out. The structural system is idealized as a finite element model composed of elastic beam elements and partially of non-linear spring elements. In the equation of motion the nonlinear restoring force term is divided into a linear term and a nonlinear term, the latter being moved to the right hand side of the equation and regarded as an external force term. The equation is solved by using the mode superposition method accompanied by the mass condensation method. The analysis method is shown to be of practical use by applying it to a scaled model and to an actual structure.