An Analytical Solution for the Initiation and Early Progression of Fretting Wear in Spherical Contacts

2021 ◽  
pp. 1-21
Author(s):  
Huaidong Yang ◽  
Itzhak Green
Keyword(s):  
Finite Element ◽  
Analytical Study ◽  
Sliding Contact ◽  
Fretting Wear ◽  
Wear Volume ◽  
Finite Element Analyses ◽  
Interfacial Sliding ◽  
Early Progression ◽  
Analytical Expressions ◽  
Sliding Distance

Abstract This work derives analytically solutions to calculate the wear volume at the initiation of fretting motion, and its progression over the first few oscillation cycles. The Arcahrd-based model considers a deformable hemisphere that is contact with a deformable flat bock. The material pairs investigated are special alloys, the Inconel617/Incoloy800H and Inconel617/Inconel617. The analytical study begins with a unidirectional frictional sliding contact, where the local interfacial sliding distance and the nominal sliding distance at the initiation of gross slip are derived. The obtained analytical expressions for unidirectional sliding are then used to derive the corresponding wear volume for the initiation and progression of gross slip and the wear volume for a general fretting cycle under pure elastic conditions. These analytical derivations are all verified by finite element analyses (FEA). The FEA method and the analytical solutions render virtually identical results for both similar and dissimilar material pairs. The effects of plasticity on the wear volume under elastic-plastic conditions are also investigated. It is found that the fretting wear volumes obtained from the FEA simulations, which include plasticity, are close to those obtained from the analytical expressions for purely elastic regimes. All the results are presented in normalized forms, which can easily be generalized and applied to 3D fretting wear of other material pairs.

Finite element analysis of fretting wear considering variable coefficient of friction

2018 ◽  
Vol 233 (5) ◽  
pp. 758-768 ◽  
Author(s):  
Ling Li ◽  
Le Kang ◽  
Shiyun Ma ◽  
Zhiqiang Li ◽  
Xiaoguang Ruan ◽  
...  
Keyword(s):  
Finite Element ◽  
Coefficient Of Friction ◽  
Variable Coefficient ◽  
Friction Model ◽  
Slip Condition ◽  
Fretting Wear ◽  
Partial Slip ◽  
Wear Volume ◽  
The Coefficient Of Friction ◽  
Contact Surfaces

Fretting wear is a kind of material damage in contact surfaces caused by microrelative displacement between two bodies. It can change the profile of contact surfaces, resulting in loosening of fasteners or fatigue cracks. Finite element method is an effective method to simulate the evolution of fretting wear process. In most studies of fretting wear, the coefficient of friction was assumed to be constant to simplify model and reduce the difficulty of solving. However, fretting wear test showed that the coefficient of friction was a variable related to the number of fretting cycles. Therefore, this paper introduces the coefficient of friction as a function of the number of fretting cycles in numerical simulation. A wear model considering variable coefficient of friction is established by combining energy consumption model and adaptive grid technique. The nodes of contact surfaces are updated through the UMESHMOTION subroutine. The effects of constant coefficient of friction and variable coefficient of friction on fretting wear are analyzed by comparing the wear amount under different loading conditions. The results show that when compared with coefficient of friction model, fretting wear is obviously affected by variable coefficient of friction and the variable coefficient of friction model has a larger wear volume when the fretting is in partial slip condition and mixed slip condition. In gross slip condition, the difference of wear volume between variable coefficient of friction model and coefficient of friction model decreases with the increase in the displacement amplitudes.

Fretting Wear Modeling of Cylindrical Line Contact in Plane-Strain Borne by the Finite Element Method

2019 ◽  
Vol 86 (6) ◽  
Author(s):  
Huaidong Yang ◽  
Itzhak Green
Keyword(s):  
Finite Element ◽  
Plane Strain ◽  
Beam Theory ◽  
Fretting Wear ◽  
Partial Slip ◽  
Wear Volume ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Line Contacts ◽  
Theoretical Predictions

This is the first study to develop an empirical formulation to predict fretting wear (volume removal) under frictional conditions for plane-strain line contacts as borne out by the finite element analysis (FEA). The contact is between a deformable half-cylinder rubbing against a deformable flat block. The FEA is guided by detailed physical conceptions, with results that subsequently lead to the methodical modeling of fretting wear. The materials in contact are first set to steel/steel, then to Alloy617/Alloy617, and finally to copper/copper. Various coefficients of friction (COFs) and the Archard Wear Model are applied to the interface. Initially, pure elastic conditions are investigated. The theoretical predictions for the wear volume at the end of the partial slip condition in unidirectional sliding contact agree very well with the FEA results. The empirical formulation for the initial gross slip distance is constructed, again revealing results that are in good agreement with those obtained from the FEA for different materials and for various scales. The Timoshenko beam theory and the tangential loading analysis of a half elastic space are used to approximate the deflection of the half-cylinder and the flat block, respectively. That theory supports well the empirical formulation, matching closely the corresponding FEA results. The empirical formulation of the wear volume for a general cycle under fretting motion is then established. The results are shown to be valid for different materials and various COFs when compared with the FEA results. Finally, plasticity is introduced to the model, shown to cause two phenomena, namely junction growth and larger tangential deformations. Wear is shown to either increase or decrease depending on the combined influences of these two phenomena.

A Finite Element Study of the Effect of Friction on the Deformations, Forces, Stress Formations, and Energy Losses in a Sliding Contact Between Aluminum and Copper Cylinders

2007 ◽  
Author(s):  
Raghvendra Vijaywargiya ◽  
Itzhak Green
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Copper Alloy ◽  
Sliding Contact ◽  
Energy Losses ◽  
Net Energy ◽  
Two Dimensional ◽  
Element Analysis ◽  
Reaction Forces ◽  
Sliding Distance

This work presents the results of a Finite Element Analysis (FEA) used to simulate two-dimensional (2D) sliding between two interfering elasto-plastic cylinders, one with material properties of a tougher material (copper alloy Glidcop) and the other of a relatively weaker material (aluminum alloy Al 6061-T651). Trends in the deformations, reaction forces, stresses, and net energy losses as a function of sliding distance are established. Results for both frictionless and frictional sliding are presented and comparisons are drawn. The effects of plasticity and friction on energy loss during sliding are isolated.

EVALUATION OF SIMPLIFIED METHODS OF ESTIMATING BEAM RESPONSES TO IMPACT

2012 ◽  
Vol 12 (03) ◽  
pp. 1250016 ◽  
Author(s):  
Y. YANG ◽  
N. T. K. LAM ◽  
L. ZHANG
Keyword(s):  
Finite Element ◽  
Computer Analysis ◽  
Analytical Study ◽  
Impact Resistance ◽  
Solid Object ◽  
Finite Element Analyses ◽  
Impact Action ◽  
Simply Supported ◽  
Static Resistance ◽  
The Impact

Fundamental principles controlling the deflection behavior of a simply supported beam responding to the impact action of a solid object is revealed in this paper. The significant mitigating effects that the mass of the beam have upon its impact resistant behavior have been illustrated with examples. It is a myth that the static resistance of the beam is indicative of its impact resistance. The important effects of "cushioning" and the higher modes phenomenon have also been identified by the analytical study presented herein. Hand calculations and computer analysis methods are introduced and evaluated by comparison with results obtained from finite element analyses using LS-DYNA.

Swage panel Analyses: Effective Orthotropic and Laminated Plate Properties

2015 ◽  
Author(s):  
Dale G. Garr ◽  
Frederick H. Ashcroft
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Analytical Approach ◽  
Plate Theory ◽  
Laminated Plates ◽  
Laminated Plate ◽  
Finite Element Analyses ◽  
Flat Plates ◽  
Analytical Expressions ◽  
Shell Geometry

Analytical expressions for the effective elastic properties of orthotropic, and laminated plates are presented for represented for representing swage panel subjected to extension and bending. A methodology is described for analyzing the swaged panels as effective, orthotropic flat plates. The equivalent rigidities of the laminated plating are established by matching the in-plane and flexural stiffness of the swage panel with those of the laminated plate. The required properties of the effective plating include the dependent Young’s modulii, shear modulus and Poisson’s ratios for each layer of a multi-layered elastic laminate. Three-ply and five-ply models are developed. This methodology allows for the use of well-known plate theory equations or assessing plate strength and stability. It also allows for the use of large-scale finite element modeling of the panels within conventional simulation packages such as those used for whole-ship structural modeling. The advantage in this analytical approach is to avoid the need for modeling the detailed, fine-scaled swage shell geometry in finite element analyses.

Simulation of Fretting Wear in Half-Plane Geometries—Part II: Analysis of the Transient Wear Problem Using Quadratic Programming

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
D. Nowell
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Analytical Solution ◽  
Quadratic Programming ◽  
Fretting Wear ◽  
Hertzian Contact ◽  
Partial Slip ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Computationally Expensive

This paper presents an efficient numerical method based on quadratic programming, which may be used to analyze fretting contacts in the presence of wear. The approach provides an alternative to a full finite element analysis, and is much less computationally expensive. Results are presented for wear of a Hertzian contact under full sliding and under partial slip. These are compared with previously published finite element analyses of the same problem. Results are also obtained for the fully worn problem by allowing a large number of wear cycles to accumulate. The predicted traction distributions for this case compare well with the fully worn analytical solution presented in part one of this paper.

A simplified numerical and analytical study for assessing the seismic response of a gravity concrete lock

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Neander Berto Mendes ◽  
Lineu José Pedroso ◽  
Paulo Marcelo Vieira Ribeiro
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Study ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Fluid Structure ◽  
Analytical Formulation ◽  
Acoustic Cavity ◽  
Water Chamber ◽  
Structure Problem

ABSTRACT: This work presents the dynamic response of a lock subjected to the horizontal S0E component of the El Centro earthquake for empty and completely filled water chamber cases, by coupled fluid-structure analysis. Initially, the lock was studied by approximation, considering it similar to the case of a double piston coupled to a two-dimensional acoustic cavity (tank), representing a simplified analytical model of the fluid-structure problem. This analytical formulation can be compared with numerical results, in order to qualify the responses of the ultimate problem to be investigated. In all the analyses performed, modeling and numerical simulations were done using the finite element method (FEM), supported by the commercial software ANSYS.

Design of flexure revolute joint based on compliance and stiffness ellipsoids

2021 ◽  
pp. 095441002110169
Author(s):  
Jing Zhang ◽  
Hong-wei Guo ◽  
Juan Wu ◽  
Zi-ming Kou ◽  
Anders Eriksson
Keyword(s):  
Finite Element ◽  
Single Point ◽  
Synthesis Method ◽  
Nonlinear Finite Element ◽  
Finite Element Analyses ◽  
Rotational Stiffness ◽  
Rotational Angle ◽  
Parameterized Model ◽  
Flexure Joints ◽  
Translational Stiffness

In view of the problems of low accuracy, small rotational angle, and large impact caused by flexure joints during the deployment process, an integrated flexure revolute (FR) joint for folding mechanisms was designed. The design was based on the method of compliance and stiffness ellipsoids, using a compliant dyad building block as its flexible unit. Using the single-point synthesis method, the parameterized model of the flexible unit was established to achieve a reasonable allocation of flexibility in different directions. Based on the single-parameter error analysis, two error models were established to evaluate the designed flexure joint. The rotational stiffness, the translational stiffness, and the maximum rotational angle of the joints were analyzed by nonlinear finite element analyses. The rotational angle of one joint can reach 25.5° in one direction. The rotational angle of the series FR joint can achieve 50° in one direction. Experiments on single and series flexure joints were carried out to verify the correctness of the design and analysis of the flexure joint.

Sign in / Sign up

Export Citation Format

Share Document