Experimental and numerical study on the vibration characteristics of an electric switchboard with wire rope isolators in naval ships

In this study, the vibration characteristics of an electric switchboard mounted on a naval ship using wire rope isolators (WRI) were investigated both experimentally and numerically. Naval ships are subjected to various types of vibrations and require high-level vibration resistance to prevent structural damage and ensure the proper functioning of key components. The WRIs used in this study exhibit high damping and are applicable to a wide range of frequencies, effectively isolating vibrations and shocks transmitted from the hull to the equipment. To implement the WRI support structure numerically, a WRI model was created to calculate the stiffness according to the direction, frequency, and initial conditions. The WRI was implemented as a spring element in the entire switchboard model, and a variable-frequency test according to MIL-STD-167-1A was performed on the model. The simulation results were compared with the experimental results, and good agreement was observed in the low- and middle-frequency ranges, with some differences in the high-frequency ranges. The issues encountered during the evaluation of the vibration characteristics of structures equipped with elastic mounts are summarized. Further studies are necessary to address issues, such as deriving the equivalent density for different frequency ranges, calculating the WRI stiffness in various directions, and resolving the local stress issues associated with modeling the WRI as a spring element.