On the Characteristics of Bolted Joints with Gaskets : Stress Analysis of a Metal Flat Gasket Interposed between Two Hollow Cylinders

Gaskets have been usually used in bolted joints in mechanical structures such as pressure vessels and pipe flanged connections. But a design of bolted joints with gaskets almost depends on experience and the sealing performance is not theoretically clarified. In this paper, a bolted joint in which a metal flat gasket is interposed between two hollow cylinders is studied. At first, a contact stress, which governs the sealing performance is analyzed as a three body contact problem using the three-dimensional theory of elasticity. Effects of the stiffness and the thickness of gaskets on the sealing performance are shown by numerical analyses. Next, the force ratio of bolted joints with gaskets, that is a ratio of an increment of bolt axial force to an external load, is analyzed. Corresponding to this analysis, experiments are carried out. Analytical results fairly coincide with experimental ones.