ULTIMATE TORSIONAL STRENGTH ANALYSIS OF CONTAINER SHIP

Container ships with wide hatch openings are thin walled open sections and have low torsional stiffness. Hence response arising from torsional loads is significant and subsequently the torsional analysis of container ship is necessary. Using the ANSYS software, the progressive collapse behaviour of a typical container vessel undertorsion was analysed. The effect of torsional moment on the ultimate strength of ship hull subjected to design vertical shear force was also determined. Full hull between the bulkheads was modeled with fully restrained warping displacement at the unloaded end. When pure torsion is applied, the hull corner regions are typically the most highly stressed areas, which may collapse. Thus, scantlings of the hull corner region should be sufficient for ship hulls with large deck openings. The ultimate strength based safety factor under pure torsion for the vessel, is 4.5, which is reduced by 30% when subjected to design vertical shear force also.