Study on the alteration of geometrical dimensions of tee stiffeners concerning the ultimate strength characteristics under a vertical bending load

Abstract

The midship section in oil tankers has become a major concern for the maximum bending moment during operational conditions. The section is assembled by a top deck structure, side structure, and bottom structure, which is usually supported by a stiffened panel, that is, a panel with an attached stiffener. This study elaborated on the conventional tee stiffener profile on the midship section of an oil tanker structure. Ultimate strength analysis was carried out using the finite element method for all the stiffeners with various geometrical dimensions according to the International Association of Classification Societies. This included the calculation of the section's modulus and mass as related variables, using an analytical approach. The results showed that the ultimate strength, section modulus, and mass were influenced by the alteration of web length and plate thickness. For example, an increase of 10 mm in web length gave an additional value of 2.22% for the ultimate strength, 2.8% for the section modulus, and 0.61% for the mass. In contrast, 1 mm of additional plate thickness increased the ultimate strength by 48.57%, section modulus by 6.91%, and mass by 3.68%.