Further Studies of the Interface Boundary Conditions for Bolted Flanged Connections

In the design of bolted flanged connections, the a-priori unknown interface contact stress condition is an important factor, determining directly whether leakage is probable and, indirectly, the stresses at critical regions such as the shell/flange junction. To provide designers with such information without the need of an often costly iterative analysis, data from numerical and physical models of typical flanged connections are analyzed. The dependence of the location, distribution and magnitude of the contact stress on the geometry of the connection and the assembly or working load level is established. Results are presented in a nondimensional form which makes them applicable to all geometrically similar flanges. Certain simple approximate relationships between the nondimensional variables describing the contact zone and the normalized contact stress distribution are noted and their usefulness as design aids explained.