Progressive collapse analysis of ship hull girders subjected to extreme cyclic bending. (September 2020)

• Record Type: Journal Article
• Authors: Li, Shen; Hu, Zhiqiang; Benson, Simon
• Is Part Of: Marine structures. Volume 73(2020)
• Publication Date: 2020-09
• Subjects: Ultimate strength -- Buckling -- Longitudinal strength -- Ship hull girder -- Cyclic load -- Progressive collapse; Naval architecture -- Periodicals; Offshore structures -- Periodicals; Architecture navale -- Périodiques; Structures offshore -- Périodiques; Naval architecture; Offshore structures; Periodicals; 620.4162
• DOI: 10.1016/j.marstruc.2020.102803
• Languages: English
• ISSNs: 0951-8339

Abstract

Abstract: This paper introduces a novel analytical method to predict the buckling collapse behaviour of a ship hull girder subjected to several cycles of extreme load. This follows the general principles of the established simplified progressive collapse method with an extended capability to re-formulate the load-shortening curve of structural components to account for cyclic degradation. The method provides a framework for assessing residual hull girder strength following a complex series of unusually extreme load events where the wave induced bending moment rises close to, or even surpasses, the monotonic ultimate strength. These load events may be sequential, such as might be caused by a series of storm waves, or they may occur as a collection of discrete events occurring over a longer period. The extreme cyclic bending amplifies the distortion and residual stress initially induced by fabrication in the flanges of the girder, which results in a deterioration of the residual ultimate strength. Validation is firstly completed through a comparison with previously published experimental work and secondly via comparison with numerical simulation on four ship-type box girders using the nonlinear finite element method. Highlights: A novel method is proposed to predict the progressive collapse response of ship hull girders under cyclic bending. Application on ship-type box girders using an extreme cyclic loading which surpasses the monotonic ultimate strength. Analyses are validated against experimental data and numerical simulations. Extreme cycles of load are shown to cause a progressive strength degradation of the box girders.