Rocking stiffness of mounting arrangements in electrical cabinets and control panels

Several studies have shown that the consideration of a rigid body-rocking mode in a cabinet is necessary to evaluate accurate incabinet spectra. Observations from finite element analyses are used to study cabinet rocking behavior and to show that accurate representation of the boundary conditions at the cabinet base is essential in the evaluation of correct rocking mode. Simple formulations for evaluating the rocking stiffness are developed by conducting detailed analytical studies for three different types of cabinet mounting arrangements. Availability of these formulations enables incorporation of a cabinet rocking mode in the Ritz vector approach [Nucl. Eng. Des. 190 (1990) 225] for evaluating the cabinet dynamic properties in significant mode and for generating the incabinet response spectra.