Session: 02-09-02 Extreme Loading and Responses 2

Paper Number: 80686

80686 - Prediction of Structural Damages and Armament Accelerations of a Surface Naval Ship due to Underwater Explosions 

Underwater explosion (UNDEX) by torpedoes yields the largest load that can be applied to a naval surface ship. The purpose of this paper is to estimate the extent of structural damages and accelerations acting on major armament systems by UNDEX for a large naval surface ships. The hull of the naval surface ship was modeled using Abaqus, a commercial finite element analysis code. By applying the Geers-Hunter UNDEX model provided by Abaqus, the primary shock wave and the secondary bubble wave based on doubly asymtotic approximation were implemented. The DSSE-HC model (Hosford-Coulomb combined with a localized necking model) enhanced for strain rate effect was applied to estimate the extent of structural damages caused by UNDEX. Since the DSSE-HC model is not supported by Abaqus, the material subroutine was independently developed. The range of structural damages predicted by the DSSE-HC model was compared with that predicted by the constant failure strain model, which has been most widely used for UNDEX problems, in order to identify a difference of the structural damage. As a result, it was confirmed that there was a large difference. That is, the constant failure strain model predicted overestimated or underestimated the extent of damage depending on the assumed failure strains. In addition, the accelerations acting on the various armament systems also showed significant differences. To predict the structural damage and acceleration of the armament system due to an UNDEX in the future, it was found that it is necessary to apply a fracture model with a advanced mechanical background rather than a simple fracture model.

Presenting Author: Hyunwoo Kim Inha University

Authors:

Hyunwoo Kim Inha University
Burak Can Cerik Inha University
Joonmo Choung Inha University