Simulation of Average Stress-Average Strain Relationship of Ship Unstiffened/Stiffened Plates Subject to in-Plane Compression

In this paper, a simple and efficient analytical method, combining elastic large deflection analysis and rigid plastic mechanism analysis, is presented for derivation of the average stress-average strain relationship of plates subject to in-plane longitudinal compression. By imposing equilibrium conditions of forces and bending moments and assuming proper stress and strain distributions in the stiffened plate cross-sections, the average stress-average strain relationship of the stiffened plates is also derived. The algorithm can be easily implemented in methods for the evaluation of ship hull girder strength, as well as in the estimation of the ultimate capacity of offshore structures.