Original article

Journal of Marine Science and Technology

, Volume 16, Issue 4, pp 379-389

Open Access This content is freely available online to anyone, anywhere at any time.

Hydroelasto-plasticity approach to predicting the post-ultimate strength behavior of a ship’s hull girder in waves

  • Kazuhiro IijimaAffiliated withDepartment of Naval Architecture and Ocean Engineering, Osaka University Email author 
  • , Kazuhiro KimuraAffiliated withDepartment of Naval Architecture and Ocean Engineering, Osaka University
  • , Weijun XuAffiliated withDepartment of Naval Architecture and Ocean Engineering, Osaka UniversityCollege of Shipbuilding Engineering, Harbin Engineering University
  • , Masahiko FujikuboAffiliated withDepartment of Naval Architecture and Ocean Engineering, Osaka University

Abstract

Dynamic collapse behavior of a ship’s hull girder in waves is investigated; post-ultimate strength behavior is the focus. Firstly, a simulation method is proposed. Assuming that a plastic hinge is formed during the collapse of the hull girder, the whole ship is modeled as two rigid bodies connected amidship via a nonlinear rotational spring. The post-ultimate strength behavior, such as the reduction of load carrying capacity due to buckling and yielding, is reflected in the model. Hydrodynamic loads are evaluated by using nonlinear strip theory to account for the effect of large plastic deformations on the loads. A scaled model for validation of the simulation is designed and fabricated. Then a series of tank tests is conducted using the scaled model to validate the simulation results. Post-ultimate strength behavior characteristics in waves are clarified by using the numerical and tank test results. It is shown that the hull girder collapses rapidly after reaching ultimate strength, and then the plastic deformation grows until unloading starts at the collapsed section. Finally, several parametric dependencies of the extent of the collapse behavior are discussed based on a series of the simulations.

Keywords

Hull girder Post-ultimate strength behavior Hydroelasto-plasticity Scaled model Collapse Tank test