Application research of vibration isolation structure in low-frequency vibration isolation of deck structure

  Objectives  This paper studies the feasibility of the vibration isolation structure loop which is used to reduce the average vibration level of deck structures and to block the transmission of low-frequency vibration of deck structures.

  Methods  The influence of forms and section parameters of vibration isolation structure loop on the low-frequency vibration transmission of deck and its adjacent bulkhead structure is explored by using numerical prediction method. By comparison, the form of vibration isolation structure loop with better vibration isolation effect is obtained. On this basis, the section parameterization of vibration isolation structure loop is carried out, and a better design scheme of deck structure with low-frequency vibration isolation is proposed.

  Results   The results show that when the vibration isolation structure increases the total weight of the main engine room by no more than 5%, a rectangular multi-stage vibration isolation structure loop with the same mass has a better vibration isolation effect than other vibration isolation structure loops. For vibration isolation structures with a width of not less than 50 mm, when 500 mm is selected as a relatively optimum height and the relatively narrow hollow square steel is selected, the effect of reducing the average vibration level of deck and adjacent bulkhead structure is improved.

  Conclusions  This research provides new insight relating to the design of low-frequency vibration isolation of the deck structures on offshore platforms.