Prediction and parametric study on the severity of collapse of a capesize bulk carrier under extreme wave loads

Abstract

A quantitative evaluation of post-ultimate strength behaviour of a bulk carrier in an extreme wave is the focus of this paper. An interaction between large elasto-plastic deformation of the ship structure and the wave load evaluation is considered by using the hydro-elastoplasticity theory. A plastic hinge is assumed to be formed amidship when the hull girder collapses in the extreme waves. The analysis is performed in two steps. In the first step, the relationship between the vertical bending moment and the curvature is obtained by using a HULLST code based on Smith's method. In the second step, a prediction of the collapse extent of the bulk carrier subjected to the extreme wave load is performed by using the hydro-elastoplasticity approach. It is clarified to what extent the subject ship hull girder may collapse in an extreme wave, some significant parameters related to the collapse extent of the bulk carrier are discussed. It can be concluded that the severity of collapse of a capesize bulk carrier under extreme wave loads can be directly related to the capacity model and load model, and is especially determined by the parameters of the capacity model.

Keywords:

• severity of collapse
• parametric study
• capesize bulk carrier
• extreme wave
• hydro-elastoplasticity
• post-ultimate strength behaviour

Acknowledgements

The authors express their sincere thanks to Professors M. Fujikubo and K. Iijima of Osaka University who offered great help in the research work. The authors were also partially funded by China Postdoctoral Science Foundation (grant number 2013M541347), the Scientific Research Foundation for Returned Overseas Chinese Scholars of Heilongjiang Province, China (grant number LC2013C18) and the State Key Laboratory of Ocean Engineering Research Funds, Shang Hai Jiao Tong University (grant number 1209).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

China Postdoctoral Science Foundation [grant number 2013M541347]. Scientific Research Foundation for Returned Overseas Chinese Scholars of Heilongjiang Province, China [grant number LC2013C18]. State Key Laboratory of Ocean Engineering Research Funds of Shang Hai Jiao Tong University [grant number 1209].