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

Abstract

Naval vessels face significant challenges owing to vibrations and shocks originating from diverse sources. Maintaining high levels of vibration and shock resistance in ship equipment is crucial to prevent damage and ensure proper functionality in demanding environments. This study experimentally and numerically investigates the shock characteristics of an electric switchboard on a naval ship using wire rope isolators (WRIs). Following the MIL-S-901D standard, impact tests were conducted using a test model. A simplified WRI model was constructed based on a previous study using the finite element method. The tests were performed in the vertical and 30° inclined orientations, and the experimental and simulation results were compared. Although an overall agreement was observed between the two, some inconsistencies were noted. These discrepancies were attributed to the inaccurate representation of the WRI. The dynamic stiffness of the WRI derived from the vibration tests conducted in this study may not be suitable for impact tests. Additionally, the modelled WRI in the simulation, as a 1D spring element with different support points, differed from the experimental setup, possibly causing localized effects that influenced the stress distribution. This study emphasizes the importance of refined WRI modelling for accurate shock simulations and offers insights into enhancing the shock resistance of naval ship equipment.