• 대한조선학회논문집
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• 제61권1호
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• pp.44-50
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• 2024

In order to reasonably predict damage extents of naval ships under in-compartment explosion (INCEX) loads, two conditions should be fulfilled in terms of accurate INCEX load generation and fracture estimation. This paper seeks to predict damage extents of various naval ships by applying the CONWEP model to generate INCEX loads, combined with the Hosford-Coulomb (HC) and localized necking (LN) fracture model. This study selected a naval ship with a 2,000-ton displacement, using associated specifications collected from references. The CONWEP model that is embedded in a commercial finite element analysis software ABAQUS/Explicit was used for INCEX load generation. The combined HC-LN model was used to simulate fracture initiation and propagation. The permanent failures with some structural fractures occurred where at the locations closest to the explosion source points in case of the near field explosions, while, some significant fractures were observed in way of the interfaces between bulkheads and curtain plates under far field explosion. A large thickness difference would lead to those interface failures. It is expected that the findings of this study enhances the vulnerability design of naval ships, enabling more accurate predictions of damage extents under INCEX loads.

• 한국해양공학회지
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• 제37권3호
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• pp.111-121
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• 2023

This paper intends to introduce the applicability of HydroQus to a problem of a tanker collision against a semi-submersible type floating offshore wind turbine (FOWT). HydroQus is a plug-in based on potential flow theory that generates interactive hydroforces in a commercial Finite element analysis (FEA) code Abaqus/Explicit. Frequency response analyses were conducted for a 10MW capacity FOWT to obtain hydrostatic and hydrodynamic constants. The tanker was modeled with rigid elements, while elastic-plastic elements were used for the FOWT. Mooring chains were modeled to implement station keeping ability of the FOWT. Two types of fracture models were considered: constant failure strain model and combined failure strain model HC-LN model composed of Hosford-Coulomb (HC) model & localized necking (LN) model. The damage extents were evaluated by hydroforces and failure strain models. The largest equivalent plastic strain observed in the cases where both restoring force and radiation force were considered. Stress triaxiality and damage indicator analysis showed that the application of HC-LN model was suitable. It could be stated that applications of suitable failure strain model and hydrodynamics into the collision simulations were of importance.