EFFECTIVE CROSS-SECTIONS OF ASYMMETRIC RINGS ON CYLINDRICAL-SHELLS

Rings or ringbeams are often used to stiffen cylindrical tanks, silos, towers, and pressure vessels. A ring acts together with the axisymmet ric shell to form a composite structure. The structural analysis of su ch a composite structure under general loadings is usually not simple, and often has to be numerical. Although the membrane stress in a symm etrical ring stiffener under axisymmetric loadings may be calculated f rom a simple effective ring analysis, no existing simple method is abl e to predict the bending stresses caused by either eccentric loading ( bending moment) or the use of an asymmetric section as a ring stiffene r. In this paper, the deformations of a general unsymmetrical ring sti ffener are analyzed using linear shell bending theory. A new rational method of determining both the precise membrane and the bending stress es throughout the discrete ring stiffener using effective ring analysi s is devised. The new method is suitable for use in a shell design sta ndard.