Elastic-Plastic Contact Conditions for Frictionally Constrained Bodies Under Cyclic Tangential Loading

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
V. Chaudhry ◽  
Satish V. Kailas
Keyword(s):  
Stainless Steel ◽  
Experimental Studies ◽  
Partial Slip ◽  
Tangential Displacement ◽  
Damage Mode ◽  
Contact Interface ◽  
Stick Slip ◽  
Contact Conditions ◽  
Elastic Plastic ◽  
Constrained Conditions

A Frictionally constrained condition implies dependence of friction force on tangential displacement amplitude. The condition may occur due to chemical, physical, and/or mechanical interaction between the contacting surfaces. The condition, sometimes also referred to as the presliding condition or partial slip condition, is characterized under fretting. Under such conditions, various experimental studies indicate the existence of two distinguishable regions, that is, stick region and slip region. In the present study, frictionally constrained conditions are identified and the evolutions of stick-slip regions are investigated in detail. Investigations have been performed on self-mated stainless steel and chromium carbide coated surfaces mated against stainless steel, under both vacuum and ambient conditions. Contact conditions prevailing at the contact interface were identified based on the mechanical responses and were correlated with the surface damage observed. Surface degradation has been observed in the form of microcracks and material transfer. Detailed numerical analysis has also been performed in order to understand the energy dissipation and the damage mode involved in the surface or subsurface damage. It has been observed that under frictionally constrained conditions, the occurrence of annular slip features are mainly due to the junction growth, resulting from elastic-plastic deformation at the contact interface. Ratcheting has been observed as the governing damage mode under cyclic tangential loading condition.

Transition of Friction and Wear by Stick-Slip Phenomenon in Various Environments under Fretting Conditions

2006 ◽  
Vol 321-323 ◽  
pp. 1344-1347 ◽  
Author(s):  
Sung Hoon Jeong ◽  
Jung Min Park ◽  
Young Ze Lee
Keyword(s):  
Friction And Wear ◽  
Mineral Oil ◽  
Fretting Wear ◽  
Engine Oil ◽  
Partial Slip ◽  
Tangential Displacement ◽  
Stick Slip ◽  
Wet Friction ◽  
Fretting Damage ◽  
Wear Tests

The fretting wear arises when contacting surfaces undergo oscillatory tangential displacement of small amplitude. Depending on the degree of stick and slip there are three kinds of the contact motions, such as gross-slip, partial-slip and stick-slip. The fretting damage occurs most severely when the transition from gross-slip to partial-slip happens. In this paper, the transitions of friction and wear under fretting were investigated by ball-on-disk wear tests in various environments, which were dry friction of air and nitrogen, and wet friction of mineral oil and engine oil. The transition from partial-slip to stick-slip firstly occurred in nitrogen environment, and then in air. Later, the transition occurred at higher load in mineral oil, and then lastly in engine oil.

Development of a model for the prediction of the fretting fatigue regimes

2001 ◽  
Vol 16 (9) ◽  
pp. 2716-2723 ◽  
Author(s):  
T. E. Matikas ◽  
P. D. Nicolaou
Keyword(s):  
Fatigue Life ◽  
Research Effort ◽  
Fretting Fatigue ◽  
Partial Slip ◽  
Geometrical Parameters ◽  
Metallic Materials ◽  
Stick Slip ◽  
Contact Conditions ◽  
Contact Materials ◽  
Fatigue Life Reduction

parameters that govern the life of metallic materials under conditions of fretting fatigue may be divided into two broad categories. The first category concerns the material properties (e.g., yield strength, elastic modulus, and surface roughness) while the second concerns the externally imposed loading conditions and contact geometry. The two in-contact materials may either stick, slip, or stick-slip (i.e., there is a slip and a stick region on their interface) against each other. It has been shown that the fatigue life reduction is highest under partial slip. The objective of the present research effort is to develop a model that enables the prediction of the particular fretting fatigue regime (i.e., slip, stick, or mixed). The parameters that affect the fretting fatigue life of metallic components were identified and integrated into a model, which allows the prediction of the interfacial contact conditions. The model was first used to identify the sensitivity of the fretting fatigue regimes upon the materials and external, and geometrical parameters. Experimental results concerned with the fatigue life were plotted on the fretting maps; the fretting fatigue regimes indicated by the latter enabled the interpretation of the experimental data.

Elastic-Plastic Finite Element Analysis of Partial Slip Rolling Contact

2001 ◽  
Vol 124 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Biqiang Xu ◽  
Yanyao Jiang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Shear Strain ◽  
Contact Surface ◽  
Rolling Contact ◽  
Slip Condition ◽  
Cyclic Plasticity ◽  
Partial Slip ◽  
Stick Slip ◽  
Elastic Plastic

The finite element model with the implementation of a robust cyclic plasticity theory was used to simulate the elastic-plastic stresses for the partial slip (stick-slip) line rolling contact. Detailed rolling contact stresses and strains were obtained for up to 40 rolling passes. The partial slip condition greatly affects the residual stress in the rolling direction and the residual shear strain within a thin layer of material near the contact surface. The residual stress in the axial direction was not significantly influenced by the partial slip condition. An increase in friction coefficient drives the location of maximum shear strain to the contact surface. In addition, a comparison was made between the finite element results and the results obtained from an approximate method.

On the Tangential Displacement of a Surface Point Due to a Cuboid of Uniform Plastic Strain in a Half-Space

2009 ◽  
Vol 77 (2) ◽  
Author(s):  
B. Fulleringer ◽  
D. Nélias
Keyword(s):  
Plastic Strain ◽  
Yield Stress ◽  
Half Space ◽  
Normal Load ◽  
Three Dimensional ◽  
Normal Displacement ◽  
Tangential Displacement ◽  
Surface Point ◽  
Stick Slip ◽  
Elastic Plastic

The elastic solution of a tangentially loaded contact is known as Cerruti’s solution. Since the contact surfaces could be easily discretized in small rectangles of uniform shear stress the elastic problem is usually numerically solved by summation of well known integral solution. For soft metallic materials, metals at high temperature, rough surfaces, or dry contacts with high friction coefficient, the yield stress within the material could be easily exceeded even at low normal load. This paper presents the effect of a cuboid of uniform plastic strain in a half-space on the tangential displacement of a surface point. The analytical solutions are first presented. All analytical expressions are then validated by comparison with the finite element method. It is found that the influence coefficients for tangential displacements are of the same order of magnitude as the ones describing the normal displacement (Jacq et al., 2002, “Development of a Three-Dimensional Semi-Analytical Elastic-Plastic Contact Code,” ASME J. Tribol., 124(4), pp. 653–667). This result is of great importance for frictional contact problem when coupling the normal and tangential behaviors in the elastic-plastic regime, such as stick-slip problems, and also for metals and alloys with low or moderate yield stress.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

Experimental Study of Static Friction in a Spherical Elastic-Plastic Contact

2008 ◽  
Author(s):  
Andrey Ovcharenko ◽  
Gregory Halperin ◽  
Izhak Etsion
Keyword(s):  
Friction Force ◽  
Normal Load ◽  
Static Friction ◽  
Tangential Displacement ◽  
Accurate Identification ◽  
Elastic Plastic ◽  
Static Friction Coefficient ◽  
Wide Range ◽  
Material Good ◽  
Contact Diameter

The elastic-plastic contact between a deformable sphere and a rigid flat during pre-sliding is studied experimentally. Measurements of friction force and contact area are done in real time along with an accurate identification of the instant of sliding inception. The static friction force and relative tangential displacement are investigated over a wide range of normal preloads for several sphere materials and diameters. It is found that at low normal loads the static friction coefficient depends on the normal load in breach of the classical laws of friction. The pre-sliding displacement is found to be less than 5 percent of the contact diameter, and the interface mean shear stress at sliding inception is found to be slightly below the shear strength of the sphere material. Good correlation is found between the present experimental results and a recent theoretical model in the elastic-plastic regime of deformation.

scholarly journals Wear and Frictional Behaviour of Metals

2014 ◽  
Vol 893 ◽  
pp. 430-435
Author(s):  
J.G. Alotaibi ◽  
B.F. Yousif ◽  
T.F. Yusaf
Keyword(s):  
Stainless Steel ◽  
Thermal Loading ◽  
Operating Parameters ◽  
Thermal Imager ◽  
Contact Conditions ◽  
Dry Contact ◽  
Three Body Abrasion ◽  
Three Body ◽  
Worn Surface ◽  
Frictional Behaviour

In the current study, wear and frictional performances of different metals are investigated under different operating parameters against stainless steel counterface under dry contact conditions. The experiments performed using block on ring machine. Microscopy was used to examine the damage features on the worn surface and categorize the wear mechanism. Thermal imager was used to understand the thermal loading in the interface during the rubbing process. The results revealed that the operating parameters influence the wear and frictional behaviour of all the metals. Brass metal exhibited better wear and frictional behaviour compared to others. Three different wear mechanisms were observed, i.e. two body abrasion (Brass), three body abrasion (Aluminium) and adhesive (Mild Steel).

Interface Temperature Measurement and Experimental Studies of Super-High Speed Polishing of CVD Diamond Films

2010 ◽  
Vol 135 ◽  
pp. 271-276
Author(s):  
Shu Tao Huang ◽  
Li Zhou ◽  
Li Fu Xu
Keyword(s):  
Stainless Steel ◽  
Temperature Measurement ◽  
Temperature Rise ◽  
Diamond Film ◽  
High Speed ◽  
Experimental Studies ◽  
Pure Titanium ◽  
Cvd Diamond ◽  
Interface Temperature ◽  
Cvd Diamond Film

Super-high speed polishing of diamond film is a newly proposed method due to its outstanding features such as low cost and simple apparatus. The interface temperature rise is due to the friction force and the relative sliding velocity between the CVD diamond film and the polishing metal plate surface. In this paper, the interface temperature rise in super-high speed polishing of CVD diamond film was investigated by using the single-point temperature measurement method. Additionally, the influence of polishing plate material on the characteristics of super-high speed polishing has been studied. The results showed that cast iron is not suitable for super-high polishing, while both 0Cr18Ni9 stainless steel and pure titanium can be used for the super-high polishing of CVD diamond film. The quality and efficiency of polishing with 0Cr18Ni9 stainless steel plate is much higher than those of pure titanium, and the material removal rate could reach to 36-51 m/h when the polishing speed and pressure are 100 m/s and 0.17-0.31 MPa, respectively.

On the scale dependence in the dynamics of rupture

2021 ◽  
Author(s):  
Federica Paglialunga ◽  
François Passelègue ◽  
Fabian Barras ◽  
Mathias Lebihain ◽  
Nicolas Brantut ◽  
...  
Keyword(s):  
Large Scale ◽  
Cohesive Zone Model ◽  
Experimental Studies ◽  
Stress Singularity ◽  
Scale Dependence ◽  
Zone Model ◽  
Stick Slip ◽  
Radiated Energy ◽  
Rupture Energy ◽  
Natural Earthquakes

<p>Potential energy stored during the inter-seismic period by tectonic loading around faults can be released through earthquakes as radiated energy, heat and rupture energy. The latter is of first importance, since it controls both the nucleation and the propagation of the seismic rupture. On one side, the rupture energy estimated for natural earthquakes (also called Breakdown work) ranges between 1 J/m<sup>2</sup> and tens of MJ/m<sup>2</sup> for the largest events, and shows a clear slip dependence. On the other side, recent experimental studies highlighted that at the scale of the laboratory, rupture energy is a material property (energy required to break the fault interface), limited by an upper bound value corresponding to the rupture energy of the intact material (1 to 10 kJ/m<sup>2</sup>), independently of the size of the event, i.e. of the seismic slip.</p><p>To reconcile these contradictory observations, we performed stick-slip experiments, as an analog for earthquakes, in a bi-axial shear configuration. We analyzed the fault weakening during frictional rupture by accessing to the on-fault (1 mm away) stress-slip curve through strain-gauge array. We first estimated rupture energy by comparing the experimental strain with the theoretical predictions from both Linear Elastic Fracture Mechanics (LEFM) and the Cohesive Zone Model (CZM). Secondly, we compared these values to the breakdown work obtained from the integration of the stress-slip curve. Our results showed that, at the scale of our experiments, fault weakening is divided into two stages; the first one, corresponding to an energy of few J/m<sup>2</sup>, coherent with the estimated rupture energy (by LEFM and CZM), and a long-tailed weakening corresponding to a larger energy not observable at the rupture tip.</p><p>Using a theoretical analysis and numerical simulations, we demonstrated that only the first weakening stage controls the nucleation and the dynamics of the rupture tip. The breakdown work induced by the long-tailed weakening can enhance slip during rupture propagation and can allow the rupture to overcome stress heterogeneity along the fault. Additionally, we showed that at a large scale of observation the dynamics of the rupture tip can become controlled by the breakdown work induced by the long-tailed weakening, leading to a larger stress singularity at the rupture tip which becomes less sensitive to stress perturbations. We suggest that while the onset of frictional motions is related to fracture, natural earthquakes propagation is driven by frictional weakening with increasing slip, explaining the large values of estimated breakdown work for natural earthquakes, as well as the scale dependence in the dynamics of rupture.</p>

Sign in / Sign up

Export Citation Format

Share Document