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.

任何用于评估船体梁极限抗扭强度的分析方法（理论或数值分析方法）的开发，都必须基于对船体梁的扭转塌陷行为的透彻了解，尤其是对于船体梁扭转所涉及的翘曲和剪切特性。崩溃过程。在本文中，首先，基于实验和数值观察，阐述了可以代表集装箱船中部舱室比例模型的单室船体梁的扭转塌陷行为。然后，通过参数研究整体船体梁的扭转坍塌机理（即全长模型），以找出导致船体梁在不同破坏机理中坍塌的主要因素和临界点（例如，翘曲或剪切破坏）。此外，还开发了一个公式来定量表征船体梁的纵向尺寸和横向框架的刚度对船体梁的极限抗扭强度的影响。结果表明，单节船体梁与整体船体梁之间的扭转塌陷机理由于翘曲效应而有很大差异。整体船体梁的纵向尺寸和横向框架会对船体梁的扭转塌陷行为和极限抗扭强度产生相当大的影响。这项研究的目的是对船体梁的扭转塌陷过程和行为进行详细而全面的了解，