Creep Analysis of Plastically Deformed Shrink-Fitted Joints

Shrink fitted joints can fail due to creep, especially when they are subjected to high temperatures. Creep strain can reduce the contact stress produced by the interference fit and loosen the fit joint. This phenomenon is very common in rotating turbines, gears, bearings, and rings, when these components are exposed to elevated temperatures. This paper presents an analytical model that describes stresses and strain in a plastically deformed shrink-fitted assembly, consisting of a solid shaft and a cylindrical hub under creep. The developed model is used to estimate the distribution of stresses and creep strain in a plastically deformed interference fit and their change over time, as creep takes place. It also predicts the change in the contact pressure and the variation of radial and circumferential stresses for different hub radii over time. The creep analysis uses Norton’s law. The results of the analytical model were graphically compared to those obtained by the finite element method (FEM), using a general-purpose FEM software.