Damage mechanisms of a typical simplified hull girder with thinner plates subjected to near-field underwater explosions

Investigating the responses of simplified hull girder (SHG) structures subjected to underwater explosions can yield valuable research insights for real ships. However, previous literature experiments predominantly utilized SHGs with plates of large relative thickness. To examine the ships' damage mechanisms, an underwater explosion experiment is conducted on an SHG with plates that closely approximate the relative thickness of those in real ships. After verifying the calculation accuracy, simulations of various cases are performed to obtain the response results. The damage mechanisms of the SHGs subjected to underwater explosions are discussed from the perspective of creases. The cumulative damage mechanism in a single underwater explosion is identified. Modes of collapse mechanisms, including hogging and sagging, are summarized, and prediction formulas for estimating the sizes of the core damage zone are provided. The results indicate that the damage phenomena on the thinner-walled SHG are more complex, resemble those observed in real ships, representing the evolution types from previous studies. For the SHG configuration employed, the hogging crease collapse mechanism exhibits an M-shaped pattern, while the sagging crease collapse mechanism displays a W-shaped pattern. The provided prediction formulas enable a quick estimation of the core damage zone size.

Automated summary

Investigating the responses of simplified hull girder (SHG) structures subjected to underwater explosions can provide valuable insights for real ships. Experimenting with an SHG that closely approximates the relative thickness of plates found in real ships, the researchers conducted underwater explosion tests to examine damage mechanisms. Through simulations and analysis, they discussed the damage mechanisms and collapse modes of the SHGs, providing prediction formulas for estimating core damage zone sizes. The results showed that the thinner-walled SHG exhibited more complex damage phenomena resembling those observed in real ships.