Elastic-Plastic Analysis of the Cylindrical Contact Between Layered Bodies

Metallic gaskets are frequently used in applications operating under extreme conditions (very high or low temperatures). The elastic-plastic contact conditions between a layered toroidal seal and its seat are presented in this paper using a bi-dimensional finite element method. This problem is similar to the contact between an elastic cylinder and an elastic substrate coated by a soft elastic-plastic layer. Three different types of behavior could be defined according to the thickness of the layer: (A) very thin, (B) very thick and (C) intermediate layer. First we propose a new equivalent elastic modulus, taking into account the properties of the layer and substrate. This new formula is a function of the ratio of the thickness of the layer to the contact width. Then, by using a dimensional approach, two criteria related to the layer thickness (very thin or very thick) are defined. Finally, for intermediate layers, the specific shape of the pressure field is explained.