Statistical Characteristics on the Compressive Ultimate Strength of Deck Panels

Abstract

When ship is a sagging condition, deck panels are applied compressive load. Compressive ultimate strength of deck panels is important as we consider about longitudinal strength. For heat affection when deck was built up by welding, deck panels are distorted and deflected. This iniitial deflection of deck panels reduce the compressive ultimate strength of the deck panels. In this study, at first we measured the initial deflection of about 450 deck panels. From these measurement we investigate shape and magnitude of initial deflection. We found various kind of initial deflection. We summarrize these results, and propose the standard shape of initial deflection and following equation of magnitude of initial deflection. ω_0/t=8×10^<-5>(b/t)^2 There are many welded lines on deck panels. Thirty five percent measured deck panels of the tanker contain welded lines. These panels have complex shape and large initial deflection. Compressive ultimate strength of these panels is lower than that of panels without welded lines. We calculate compressive ultimate stength of measured by F.E.M., and investigate the statistical characteristics of the compressive ultimate strength. Variations of yield stress and initial deflection are the most effective factors on the statistical compressive ultimate strength of the deck panels.