Study of L-extension type ship vibration isolation pedestal based on impedance mismatch principle

  Objectives  As the traditional pedestal has limited vibration suppression ability, it is necessary to design a new type of pedestal structure to improve its performance in this aspect.

  Methods  First, based on the principle of impedance mismatch, a kind of L-extension structural cell is constructed. The mechanical properties of the straight-wall pedestal and new integrated pedestal are then compared and analyzed, therefore, the new type of pedestal is designed as lightweight to obtain a block pedestal. Finally, by changing the ratio of the thickness of the L-shaped structure in the cell, the vibration isolation effects of the new block pedestal are further improved.

  Results  The results show that under the premise that the weight of the pedestals are similar, the total vibration level drop of the new pedestal in the whole frequency band of 10-250 Hz is increased by 40.56% compared with that of the straight-wall pedestal.

  Conclusions  It concludes that the L-extension cell structure proposed in this paper has obvious inhibitory effects on vibration wave transmission, and that the L-extension cell structure can provide references for the design of new marine vibration isolation pedestals.