On the Maximum Deflection of Plating in Newly Built Ships

Abstract

Various efforts have been made in the past to express the central deflection of the plate panel as a function of the basic parameters, such as plate slenderness, welding thickness, etc., upon which it depends. Distortion tolerances of the plate could thus be specified as a function of the central deflection, which is easily established. The present paper analyzes more than 2000 measurements of plate panel central deflection in newly built ships collected over a number of years in a shipyard. The central deflection is expressed as a function of the plate slenderness ratio, the thickness of the stiffeners, the plate aspect ratio, and the weld throat thickness. A regression analysis is carried out to determine the coefficients of the functional relationship. From the regression analysis the influence of each parameter on the deflection is derived and new formulas for predicting maximum deflection in various cases are proposed. Finally, results of the analysis with various parameters included are compared with similar formulations previously given in the literature, and a new formula for specification of post-welding distortions is suggested.