Warping and shear behaviors involved in hull girder's torsional collapse process

Abstract

Any research and development of the analysis methods, theoretical or numerical ones, for evaluating hull girder's ultimate torsional strength must be based on a thorough understanding of the torsional collapse behaviors of the hull girder, especially for the warping and shear characteristics involved in hull girder's torsional collapse process. In this paper, firstly, the torsional collapse behaviors of a single-compartment hull girder that could represent a scale model of the mid-ship compartment of a container ship are illustrated based on both experimental and numerical observations. Then, torsional collapse mechanisms of the global hull girder (i.e., the full-length model) are parametrically studied to figure out the major factors and the critical point that make the hull girder collapse in different failure mechanisms (i.e., warping or shear failure). Also, a formula is developed to quantitatively characterize the effect of hull girder's longitudinal dimension and transverse frameworks' rigidity on the ultimate torsional strength of the hull girder. Results show that the torsional collapse mechanisms between the single-segment hull girder and the global hull girder are very different due to warping effect. The longitudinal dimension and transverse frameworks of the global hull girder can have a considerable effect on hull girder's torsional collapse behaviors and ultimate torsional strength. The objective of this research is to make a detailed and comprehensive understanding of hull girder's torsional collapse process and behaviors, figuring out the major factors and the critical point that govern warping or shear failure mechanisms of the hull girder under torsion.