Shock resistance evaluation method of ship air bottle-base connection structure

  Objectives  As an important component connecting the equipment and structure of a submarine, the shock resistance of the base structure has an important impact on the ship's survivability. It is simple and efficient to calculate the shock resistance of the base and equipment using the equivalent static load method, but it has higher accuracy only if the lower order response is the main failure mode.

  Methods   In this paper, the relative error of structural stress between the static G method and Dynamic Design Analysis Method(DDAM) design spectrum method is studied by taking the air bottle-base structure as the object of analysis. When the low order modal mass of the base structure is occupied in different proportions, the relative error and stress distribution between the equivalent static load and DDAM design spectrum method is analyzed. Taking the actual shock environment of the submarine structure as the input load, the equivalent relation between the DDAM design spectrum and actual shock environment is analyzed.

  Results   Precise results are obtained by using the static G method when the single modal mass of the ship's equipment structure is relatively large. For equipment constructed on the deck of a submarine, the shock load stipulated in GJB 1060 is basically equivalent to the shock environment when the shock factor is 0.7 and the explosion source is on the same cross-section as the base structure.

  Conclusions   This research can provide useful references when selecting shock resistance evaluation methods for shipboard equipment.