How Loads Interact? A Numerical Investigation of Aluminum Stiffened Panels Under Bi-Axial and Lateral Loads

Abstract

Due to low weight, aluminum alloys are commonly used to build ferries, working boats and high-speed ships. The hull of such vessels can be designed as catamaran and trimaran for favorable hydrodynamical behavior and operational purposes. Non-monohull structures are in certain areas more exposed to combined loads, such as the cross-deck subjected to the longitudinal and transverse hull bending, and water slamming. In these cases, the existing design rules predict the ultimate strength with simplified interactions between bi-axial and lateral loads. A further complicating effect is the reduced material strength and residual stresses in the heat affected zones (HAZ). Thus, it is still necessary to investigate the ultimate strength of aluminum stiffened panels subjected to combined loads and get a better understanding of the interaction mechanics, which again may lead to improved design rules.

Based on a previously developed numerical model, the structure response of an aluminum multi-span panel subjected to combined longitudinal, transverse, and lateral loads is simulated with the nonlinear finite element method. The welding effects are considered, including both geometrical and mechanical imperfections. By changing the combined load values, the interactions between bi-axial loads are examined. The influences of lateral pressure level on the structure response are also investigated. The failure process, ultimate strength, and stress components between different cases are compared.