Numerical analysis of plastic deformation on a journal bearing surface

Abstract

As a material of bearing alloy for layer-structured journal bearings, soft metals such as white metal are commonly used. If a pressure of fluid on a bearing surface becomes high due to severe service condition, a layer of bearing alloy may suffer macro-scale plastic deformations, because its yield stress is relatively low than back metal and housing. Because a behavior of a shafting is strongly affected by the shape of bearing surface, discussions about a development of plastic deformation will provide interesting information for design and maintenance of bearings. In this paper, static analyses of journal bearings are performed including a consideration of plastic deformation. As a simulation model, a bearing structure is divided into two layers. The first layer means bearing alloy, which is expressed by one-dimensional stress strain characteristic. And the second layer means combined structure of back metal and housing. From the results of calculation, the ratio of stiffness between the two layers becomes useful indicator to predict a behavior of bearing surface. And effects of residual plastic strain become significant in case the stiffness of second layer is high.