Fretting Fatigue and Contact Conditions: A Rational Explanation of Palliative Behaviour

1985 ◽  
Vol 199 (4) ◽  
pp. 325-337 ◽  
Author(s):  
T C Chivers ◽  
S C Gordelier
Keyword(s):  
Friction Coefficient ◽  
Fretting Fatigue ◽  
Relative Displacement ◽  
Literature Survey ◽  
Clamping Force ◽  
Contact Conditions ◽  
Tensile Stresses ◽  
Slip Regime ◽  
Rational Explanation ◽  
Complicated Situation

This paper considers what palliative effects can be achieved for fretting fatigue by modifying the contact conditions. A previous literature survey of palliatives by the authors is briefly reviewed to demonstrate the contrary nature of much of the evidence. Two simple geometries (sphere and cylinder on plane) are then considered, and the tensile stresses generated in the wake of the sliding contact derived. It is contended that fretting fatigue is the result of such tensile stresses contributing to the crack initiation process. The effect on these tensile stresses of modifying the contact conditions of the friction coefficient and clamping force is examined, so that successful palliatives can be identified. The analysis shows that conditions exist where increasing or decreasing either the friction coefficient or clamping force can be of benefit, and there is no panacea. The correct action depends on geometry, slip regime and the controlling factor for relative displacement. The analysis therefore provides an explanation of the apparent contradictions in the literature. Suggestions are made for the best approach to ameliorate a fretting fatigue problem, given this complicated situation.

A Quantitative Theory for the Computation of Tire Friction Under Severe Conditions of Sliding

1986 ◽  
Vol 14 (1) ◽  
pp. 44-72 ◽  
Author(s):  
C. M. Mc C. Ettles
Keyword(s):  
Friction Coefficient ◽  
Flash Temperature ◽  
Contact Conditions ◽  
Quantitative Form ◽  
Heating Effects ◽  
Rubber Friction ◽  
Viscoelastic Effects ◽  
Tire Friction ◽  
Pavement Friction ◽  
Metal Polymer

Abstract It is proposed that tire-pavement friction is controlled by thermal rather than by hysteresis and viscoelastic effects. A numerical model of heating effects in sliding is described in which the friction coefficient emerges as a dependent variable. The overall results of the model can be expressed in a closed form using Blok's flash temperature theory. This allows the factors controlling rubber friction to be recognized directly. The model can be applied in quantitative form to metal-polymer-ice contacts. Several examples of correlation are given. The difficulties of characterizing the contact conditions in tire-pavement friction reduce the model to qualitative form. Each of the governing parameters is examined in detail. The attainment of higher friction by small, discrete particles of aluminum filler is discussed.

scholarly journals On rolling friction

2019 ◽  
Vol 485 (3) ◽  
pp. 295-299
Author(s):  
A. P. Ivanov
Keyword(s):  
Friction Coefficient ◽  
Angular Velocity ◽  
Viscous Friction ◽  
Rolling Friction ◽  
The Body ◽  
Normal Velocity ◽  
Contact Conditions ◽  
Combined Motion ◽  
Pure Rolling ◽  
Over Time

The dependence of rolling friction on velocity for various contact conditions is discussed. The principal difference between rolling and other types of relative motion (sliding and spinning) is that the points of the body in contact with the support change over time. Due to deformations, there is a small contact area and, entering into contact, the body points have a normal velocity proportional to the diameter of this area. For describing the dependence of the friction coefficient on the angular velocity in the case of “pure” rolling, a linear dependence is proposed that admits a logical explanation and experimental verification. Under the combined motion, the rolling friction retains its properties, the sliding and spinning friction acquiring the properties of viscous friction.

Fretting Wear Mechanisms and Their Effects on Fretting Fatigue

1988 ◽  
Vol 110 (3) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Berthier ◽  
Ch. Colombie´ ◽  
L. Vincent ◽  
M. Godet
Keyword(s):  
Fretting Fatigue ◽  
Relative Displacement ◽  
Contact Condition ◽  
Fretting Wear ◽  
Initial Contact ◽  
Great Care ◽  
Third Body ◽  
Body Formation ◽  
The Third ◽  
Contact Surfaces

Fretting wear and fretting fatigue are governed by the rate of formation of materials (third-bodies) between the initial contact surfaces. Furthermore, the third-bodies must be maintained within the contact. The issue of the race between third-body formation and subsurface damage conditions the effect of fretting on fatigue. That race lasts for only a few hundred or at best a few thousand cycles. Effective third-bodies (or good anti-fretting lubricants) must adhere strongly to the rubbing surfaces, and be able to accommodate at least part of the relative displacement. Great care in the design of test equipment has to be exercised before definitive results on the effect of amplitude and frequency on either fretting fatigue or fretting wear can be obtained for a given contact condition, given materials and given environments.

Study on Reducing Relative Displacement of Isolation Device With Friction Surface of Inclination

2008 ◽  
Author(s):  
Masanori Shintani ◽  
Hiroki Tanaka
Keyword(s):  
Friction Coefficient ◽  
Analytical Model ◽  
Friction Force ◽  
Coefficient Of Friction ◽  
Friction Surface ◽  
Relative Displacement ◽  
Random Wave ◽  
Proportional Relation ◽  
Optimal Coefficient ◽  
Isolation Device

This paper deals with an isolation device by using friction force. An isolation device decreases response acceleration and external force. Therefore, earthquake damage is reduced. However, an isolation device has a demerit for large relative displacement. The purpose of this research is to decrease the relative displacement by using the friction force. Then, an analytical model in consideration of the friction force is proposed, and a simulation is analyzed with well-known earthquake waves. Consequently, it is thought that optimal friction force exists, and this force decreases both the response acceleration and the relative displacement. This is considered to change with the properties of earthquake waves. Then, it analyzed using the regular random wave. The result, the proportional relation was seen between relative displacement and the optimal coefficient of friction. Then, by changing a friction coefficient according to relative displacement, it is thought that both response acceleration and relative displacement can be reduced. However, it is difficult to change a friction coefficient. So, in this research, reduction of response acceleration and relative displacement is aimed by changing the angle of a friction surface and friction force. Furthermore, an angle is changed in the middle of a slope. It is thought that it becomes possible to reduce response acceleration and relative displacement further. An experimental device is made under the same conditions as the proposed analytical model. The experimental results are compared with the analytical results.

scholarly journals Static Strength of Friction-Type High-Strength Bolted T-Stub Connections under Shear and Compression

2020 ◽  
Vol 10 (10) ◽  
pp. 3600 ◽  
Author(s):  
Gangnian Xu ◽  
Youzhi Wang ◽  
Yefeng Du ◽  
Wenshuai Zhao ◽  
Laiyong Wang
Keyword(s):  
Friction Coefficient ◽  
Ultimate Strength ◽  
Compression Ratio ◽  
Failure Modes ◽  
Load Condition ◽  
High Strength ◽  
Shear Capacity ◽  
Displacement Curve ◽  
Clamping Force ◽  
Bolt Diameter

The friction-type high-strength bolted (FHSB) T-stub connection has been widely used in steel structures, due to their good fatigue resistance and ease of installation. While the current studies on FHSB T-stub connections mainly focus on the structural behaviors under both shear and tensile force, no research has been reported on the mechanical responses of the connections under the combined effects of shear and compression. To make up for this gap, this paper presents a novel FHSB T-stub connection, which is simple in structure, definite in load condition, and easy to construct. Static load tests were carried out on 21 specimens under different shear–compression ratios, and the finite-element (FE) models were created for each specimen. The failure modes, initial friction loads and ultimate strengths of the specimens were compared in details. Then, 144 FE models were adopted to analyze the effects of the friction coefficient, shear–compression ratio, bolt diameter and clamping force on the initial friction load and ultimate strength. The results showed that the FHSB T-stub connection under shear and compression mainly suffers from bolt shearing failure. The load–displacement curve generally covers the elastic, yield, hardening and failure stage. If the shear–compression ratio is small and the friction coefficient is large, its curve only contains the elastic and failure stage. The friction coefficient and shear–compression ratio have great impacts on the initial friction load and ultimate strength. For every 1 mm increase in bolt diameter, the initial friction load increased by about 10%, while the ultimate strength increased by about 8.5%. For each 10% increase/decrease of the design clamping force, the initial friction load decreases/increases by 7.8%, while the ultimate load remains basically the same. The proposed formula of shear capacity and self-lock angles of FHSB T-stub connection can be applied to the design of CSS-enhanced prestressed concrete continuous box girder bridges (PSC-CBGBs) and diagonal bracing.

Fretting Fatigue on Thin Sheets

2015 ◽  
Vol 651-653 ◽  
pp. 504-509
Author(s):  
Eduardo Luis Gaertner ◽  
José Divo Bressan ◽  
Anne Karollyne Petry
Keyword(s):  
Sheet Thickness ◽  
Experimental Tests ◽  
Fretting Fatigue ◽  
Relative Displacement ◽  
Thin Sheets ◽  
Stainless Steel Sheet ◽  
Small Reduction ◽  
Dedicated Machines ◽  
Number Of Cycles ◽  
Two Bodies

The fretting is responsible for many failures of components in the industry. It is present in assemblies like rivet and screw fixture, dovetailjoint, shaft and hub with key, and all connections of two bodies with a contact force and a small induced relative displacement. Topic of studies for decades, the researchers perform experimental tests with some simplification in order to accelerate the phenomenon, some times using standard devices or creating dedicated machines for better representing the behavior of the desired components. There are a few studies with thin sheets, in which the fretting fatigue has more impact because a small reduction of the cross section due to the wear of crack results in a significant increase of stress and rate of crack propatation, decresing the number of cycles until failure. In this work, it wasbuild a device to generate the fretting fatigue with two different shape of contact pad. The specimen is a stainless steel sheet thickness 0.152mm, which fractures and surfaces were analyzed using the SEM and white light interferometer to understand the fractures.

Life Assessment in Fretting Fatigue

2014 ◽  
Vol 618 ◽  
pp. 99-122 ◽  
Author(s):  
Carlos Navarro ◽  
Jesús Vázquez ◽  
Jaime Domínguez
Keyword(s):  
Fatigue Strength ◽  
Detrimental Effect ◽  
Fretting Fatigue ◽  
Life Assessment ◽  
Stress Fields ◽  
Strength Analysis ◽  
Cyclic Loads ◽  
Cyclic Variation ◽  
Contact Conditions ◽  
The Many

Fretting fatigue denotes the detrimental effect on a material arising from the cyclic sliding of two contacting surfaces with small relative displacements between them. One or both of the components in contact may be subject to bulk stresses caused by cyclic loads. The assessment of the fretting fatigue strength and life of any component is a complicated issue due to the many parameters affecting it, the complexity of the stress fields cyclic variation during fretting and the uncertainties associated to the contact conditions. This paper describes some singular aspects of fretting fatigue related to strength analysis and testing, presents a procedure developed by the authors during the last years to estimate the fretting fatigue strength and life and compares the assessment outcomes with the results of tests carried out by different authors.

scholarly journals Study on tribo-chemical and fatigue behavior of 316L austenitic stainless steel in torsional fretting fatigue

2019 ◽  
Vol 234 (1) ◽  
pp. 84-93
Author(s):  
Zhibiao Xu ◽  
Jinfang Peng ◽  
Jianhua Liu ◽  
Xiyang Liu ◽  
Wulin Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Damage Zone ◽  
Fretting Fatigue ◽  
Partial Slip ◽  
Connected Components ◽  
Slip Regime ◽  
316L Austenitic Stainless Steel ◽  
Torsional Fretting ◽  
Fretting Damage

Fretting fatigue is a complex tribological phenomenon that can cause premature failure of connected components. Combining with the effects of tribological and fatigue, the components have premature fracture, which ultimately leads to disastrous consequences. In this work, the fretting fatigue tests of 316L austenitic stainless steel have been carried out with same normal load and varied torsional torques. The results indicate that the fretting fatigue life significantly depends on the torque amplitude, wear degree of the fretting damage zone, hysteresis loops and energy dissipation. A physical model for fretting crack initiation and propagation is created to explain the failure process of torsional fretting fatigue. The results from X-ray photoelectron spectroscopy analysis show that the extent of oxidation in the fretting damage zone is affected by the amplitude of relative displacement. The tribo-chemical reaction in the slip regime is more activated than that in partial slip regime. It can lead to more severe wear in the slip regime. The wear debris of the fretting damage zone is composed of metallic Fe, Fe2+ and Fe3+.

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