Experimental and numerical investigation on crack initiation of fretting fatigue of dovetail

Abstract

The present study investigated the fretting fatigue crack initiation of dovetail structure based on experimental observation and multiple axial criteria. Two typical critical plane approaches of the Smith‐Watson‐Topper (SWT) and the Fatemi and Socie (FS) model were used to predict the crack initiation location, orientation angle, and fatigue life. The results indicate that both SWT and FS models predict consistent results with the experiment in crack initiation location. Regarding the crack initiation angle, FS model shows good agreement with the experimental observation, but SWT model exhibits a large difference. The two models give conservative results in fretting fatigue life. In view of this, the theory of critical distance (TCD) was incorporated into the SWT and the FS models. It shows that both the TCD‐SWT and the TCD‐FS predict fatigue lives within a scatter band of 2. It suggests that introducing the TCD into the critical plane model can greatly reduce the conservatism of the prediction. Furthermore, the prediction has less dependence on specific models.

Evaluation of the Fatemi‐Socie damage parameter for the fatigue life calculation with application of the Chaboche plasticity model

“…[38][39][40][41][42] Fatemi and Socie 5 define the critical plane by the plane with the highest shear strain amplitude. 13,14,47 In multiple articles, 8,12,22,36,37 the problem of searching the critical plane for the Fatemi-Socie model is simplified by the assumption that the critical plane is perpendicular to a specimen surface, and as a result, the plane orientation is described by only a single angular displacement. But, under the nonproportional loading, the rotating principal axes of strain tensor cause that a shape of the resolved shear strain path on the arbitrary plane generates nonuniqueness of the measure of the shear strain amplitude.…”

Experimental and computational investigation of fretting fatigue characterized by nominal contact pressure in dovetail structures

“…The stress concentrations and uncertain manufacturing tolerances make the test results cannot be related to other structures. [8][9][10][11][40][41][42][43][44][45][46][47][48] Moreover, a fretting model based on a sophisticated constitutive model and damage evolution equations is too time consuming and not efficient enough for engineering design. In the turbine industry, fretting fatigue was assessed based on a simple estimate of the contact pressure over yield stress of the material.…”

Fretting‐fatigue analysis of shot‐peened aluminium and titanium test specimens

“…This situation is referred to as fretting fatigue, which is well known to be different from plain fatigue, mainly due to the high stress level that characterises the region near the contact surface. 3,[8][9][10] Fretting fatigue is recognised as a primary failure mode across a wide range of mechanical systems, such as dovetail joints, 11,12 bolt and riveted joints, [13][14][15] clamped joints, 16 bearings, 17 metallic cables [18][19][20] and turbine components. 21 Many attempts were made in order to carry out possible alleviation measures, in order to improve the fatigue life of fretting affected components.…”