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The phenomenon of fretting fatigue involves multiaxial stress states near the contact interface and is mainly characterized by nucleation and propagation phases. Based on the mechanism of each phase, various approaches have been developed to predict damage initiation location and life. This paper aims to investigate the effectiveness of continuum damage mechanics (CDM) approach under in phase and 90° out of phase loading. Two cases with different material and loading conditions are considered for this analysis. The first case includes constant normal load and phase difference is generated between axial cyclic stress and tangential load. Whereas in the second case, cyclic normal load is applied and phase difference is generated between normal load and other two loads i.e. cyclic axial stress and tangential load. The results obtained using CDM approach are compared to those obtained using critical plane (CP) approach. The numerical results are also compared with experimental results from literature. It is observed that, both approaches provide good estimate of initiation location and life for in phase loading. With phase difference of 90°, the initiation locations also match well with the experimental results, however, for life estimation CDM approach has shown better prediction than CP approach, especially at lower loads. In addition, both approaches have shown that with phase difference of 90°, the fretting fatigue life increases as compared to in phase loading. [ABSTRACT FROM AUTHOR]

In this paper, a numerical crack growth analysis is conducted by using the Maximum Tangential Stress (MTS) criterion and its extension, which considers the contact stress between the crack surfaces. Moreover, fretting fatigue is a multiaxial non-proportional loading problem, and most components are subjected to asynchronous loads. Therefore, this paper mostly focuses on the influence of loading phase difference (Φ) on the crack propagation behavior. Meanwhile, for the fretting fatigue problem, as there is a relationship between the crack initiation and propagation, the effect of initiation characteristics, including crack initiation position and direction is studied under different loading phase differences using Linear Elastic Fracture Mechanics (LEFM) theory. It is observed that the predicted crack path and lifetime by using the extended MTS criterion and Paris' law is in good agreement with the experimental results in the literature. It is found that the phase difference has a strong effect on the crack propagation behavior. Furthermore, we found that the crack initiation position has a greater influence on crack propagation behavior than the crack initiation direction. [ABSTRACT FROM AUTHOR]

We present numerical computation of stresses under fretting fatigue conditions derived from closed form expressions. The Navier-Cauchy equations, that govern the problem, are solved with strong and weak form meshless numerical methods. The results are compared to the solution obtained from well-established commercial package ABAQUS, which is based on finite element method (FEM). The results show that the weak form meshless solution exhibits similar behavior as the FEM solution, while, in this particular case, strong form meshless solution performs better in capturing the peak in the surface stress. This is of particular interest in fretting fatigue, since it directly influences crack initiation. The results are presented in terms of von Mises stress contour plots, surface stress profiles, and the convergence plots for all three methods involved in the study. • Numerical computation of fretting contact. • Navier-Cauchy equations. • Strong and weak form meshless solution. • Strong form performs better in capturing peak stress. [ABSTRACT FROM AUTHOR]