Elastic-plastic connection model describing dynamic interactions of component connections

Design evaluation of nuclear facilities would be facilitated by a numerical evaluation system that can evaluate both global and local behaviors under severe seismic loading. A critical part of such a system is the numerical model describing the dynamic physical interactions among component connections, called the elastic-plastic connection model. Here we propose such a model and use it to simulate dynamic interactions using real earthquake and plant data from the High Temperature Engineering Test Reactor (HTTR) at the Oarai Research and Development Center of the JAEA. We focus on joints connecting the component supports and the building walls, which generally involve fixed/pinned boundary conditions. Precision was increased by adjusting model parameters to fit experimental data. The results confirmed a reduction in the vibration response and a change in the natural frequencies of individual components under large virtual earthquake loading, which are considered to have resulted from dynamic interactions between the joints connecting the component supports and the building walls. (author)