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Numerical analysis of geometrical parameters effect on contact zone under fretting fatigue loading

Ikhlef Chaouch Mohamed, Baltach Abdelghani, Benhamena Ali

Advances in Materials Science

2022

Vol. 22, nr 4(74)

5--20

The fatigue process under fretting conditions is characterized by small oscillatory movements due to vibrating or cyclic loads between two surfaces in contact. Two phenomena can arise as a consequence: the surface wear of the bodies in contact, giving rise to the so-called fretting wear. The second phenomenon concerns crack nucleation in the contact region, causing a reduction in the fatigue strength of the component subjected to cyclic loading. This process is called “fretting fatigue”. In the present study, finite element models (2D-FEM) are provided to demonstrate the effect of pad radius on the contact parameters such as: contact pressure, shear traction, stresses, sliding, size of contact line and crack nucleation and its location along the contact line of aeronautical Al2024 alloy under fretting fatigue loading. Six numerical models are utilized to describe the effect of changing pad radii on contact stresses and damage of crack nucleation. The Ruiz parameter criterion should be used to predict the location of crack initiation in the contact zone. Comparison of the finite element results shows that there is a good agreement between the numerical modeling predictions with those analytical results. The stress field, relative slip, and damage parameters in fretting fatigue loading were highlighted. The pad radius substantially affects the distribution of contact parameters. Particular attention must be taken into consideration to this variable when analyzing the structure in fretting fatigue.

The fretting fatigue of the bolted assemblies

Benhamena A., Aminallah L., Aid A., Benguediab M., Amrouche A., Benseddiq N.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

2011

z. 99

17-17

One of the principal failures of bolting assemblies is the fretting. The combi- nation of vibration and service load can introduce the damage of fretting fatigue on the contact surfaces of the assembly which trend to evoke a nucleation of crack and then the structure fracture. Contact pressure or clamping force and displacement at the interface or relative slip are two important factors which control the fretting wear and the fretting fatigue. This paper describes the effect of clamping force (tightening torque) on the fretting fatigue behavior of bolted assemblies.

Evaluation of contact slips during fretting fatigue test

Spaniel M., Jurenka J., Kuzelka J., Ruzicka J., Nesladek M.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

2011

z. 99

56-58

Fretting fatigue can be defined as fatigue damage near contact interface acelerated due to small relative tangential movements of contacting surfaces. Stress field at the vicinity of contact interface, friction and partial slipping of contact surfaces are commonly evaluated as factors having significant influence on local damage resulting into the crack iniciation. Fretting fatigue occurs particullarly in typical machines parts as pressed joints, turbine blades lock joints, slot couplings, etc. Evaluation of fatigue damage under fretting conditions based on phenomenological criteria is target of presented research. Verification of fretting fa- tigue criteria have to be based on reliable experimental and computational results. Quantities describing local material loading as stress field, contact slips, etc., the measurement of which is very difficult, are in practice often calculated using finite element method. It is dependent on phenomenological description of friction. That is why we decided to verify numerical model of experimental setup from the point of view of friction.