Research on Methods of Determining Design Stress of Square Shell

Abstract The analysis and design of square cross section vessels have always been difficult and complicated due to the lack of theoretical solutions. Current design codes rely on empirical formulas for stress calculations developed based on analysis results of prismatic cross section frames. The accuracy and applicability of empirical formulas are not satisfied in most engineering applications. With the recently proposed closed-form solutions for square shells, it has become possible to optimize the analysis and design of square cross section containers. In this paper, two dimensionless parameters are introduced into the closed-form solutions. The stress in a square shell is a function of those two parameters. Parametric analysis was performed to investigate the stress characteristics in the square shell. Empirical expressions are proposed to simplify stress analysis. By using the conception of virtual rolled square, the theoretical solution of rolled square shell is extended to welded square shell. By performing regression analysis on the parameter research results, the corresponding empirical expression for design stress calculation of welded square shells was established. The accuracy and applicability of the empirical formulas proposed in this paper are confirmed.