ABSTRACT
The behaviour of steel plates under axial compression and tension with typical geometry equivalent to ship structures has been examined thoroughly in the literature. For example, Faulkner, (1975) derived a highly effective design formula (based on the Frankland formula) for predicting the ultimate strength of a long plate, which captures elasto-plastic collapse of stocky plate and post buckling strength of more slender plating. Test data are presented in several studies, for example by Frieze et al., (1977). Chalmers, (1993) presents typical load shortening curves for plates over a range of non-dimensional slenderness which can
1 INTRODUCTION
The ultimate strength of a ship is normally defined by the capacity of the main hull girder under longitudinal hogging and sagging bending moment. Several methods are available to evaluate the ultimate strength and compare to the extreme wave induced loading. These include the simplified progressive collapse method (also known as the incremental-iterative method in some classification rules) and nonlinear finite element method. Both these methods normally consider pure longitudinal bending moment as the principal load case. However, particularly in the case of damage, longitudinal bending may not be the governing load condition. Torsion and shear forces may appreciably influence the global strength. Therefore the effect of combined loading is an important factor to be investigated.
