Effects of Hub Contact Shape on Contact Pressure and Fatigue Life in a Press-Fitted Shaft

Abstract

The objective of this study is to clarify the effect of hub contact shape on contact pressure and fatigue life with regard to the selection of a suitable taper design near the end of the fit. A numerical asymmetric-axisymmetric finite element model was developed in order to determine the contact stress state of press-fitted shaft by using four types of tapered contact surfaces on the hub. The variations of fatigue crack initiation life according to the change of tapered contact surfaces on the hub were evaluated by using the Smith-Watson-Topper (SWT) multiaxial fatigue criterion. As the result, comparing with the contact pressure and the fatigue crack initiation life, maximum decrease of contact pressure and maximum increase of fatigue crack initiation life were obtained for the 1/400 m/m tapered hub subjected to a bending load near the fretting fatigue limit. Furthermore, as the change of bending load, the optimal amout of taper in hub which fatigue life gets into maximum is varied. Therefore, we suggest that the best performance, in terms of pressure distribution and fatigue life of press fit, can be obtained by using a proper taper values for the hub element.