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13.02.2022A randomly generated surface roughness, 128 by 128, Sq=50nm124 downloads

20.01.2022The simulation app for mixedEHL rollingsliding line contacts has been developed based on the capabilities of the CamRollerInterface Tribotester (CRT01). The CRT01 as well as the simulation app, allow the user to evaluate the resulting slidetoroll ratio (SRR) and traction coefficient (among others) generated in a lubricated roller on roller (i.e., disc on disc) configuration when a load torque is applied to the driven roller. Differently from classic twin disc machines, the CRT01 allows the generation of slippage throughout the application of a load torque (i.e., braking torque) to one of the rollers. This means that slippage is not a fixed variable during the test but, a result of the applied braking torque. Hence, changes in the tractive behavior of surfaces produced by wear (or other factors) can be studied based on the variations of the SRR measured through the test. The interested user can refer to https://www.tribonet.org/news/testingofcamrollerfollowersystems/ and https://www.youtube.com/watch?v=LViW5rxueoM for more information about the testing method and the test setup. Instructions for use: The mixedEHL simulator for rolling sliding line contacts is divided into 3 different panels. The reference conditions, the controls, and the results. Reference Conditions: A set of reference conditions is given by default. They include contact conditions, material properties, and lubricant properties. The user can modify these values and click "Run" to display the results. Control Panel: The app allows the adjustment of 5 parameters for the simulation, namely, the load (L), the speed (ωR1), the temperature of the lubricant, the load torque, and the offset angle (Ψ). Note that with Ψ=0, the contact force is equal to the load (L). After adjusting the controls, the results can be obtained by clicking "Run". Results The results panel displays several results that can be used to evaluate the tribological behavior of the simulated contact. They include the lambda ratio, the traction coefficient, and the slidetoroll ratio, among others. Note that the slidetoroll ratio increases when higher load torques (i.e., braking torque) are applied. Read More82 downloads

12.02.2018On behalf of Professor George Adams. This is an overview of contact mechanics models in case of two spheres. The overview starts with Hertz model and continues to adhesive models and GreenwoodWilliamson. A very good good summary for the case of two spheres. Read More448 downloads

19.04.2021Contact mechanics code useful for calculating subsurface stress424 downloads

03.06.2017This thesis considers lubrication and wear in artificial joint replacements. The lubrication theory and model development is described in details and can be useful for anyone starting in the area of lubrication modeling. Read More201 downloads

01.06.2017'The correct lubricant' covers basic practical information about lubricants in automotive and industrial areas. It is written for users of lubricants, giving only what is essential to know and useful for them. It could also be used by professionals in the field who must explain various aspects of lubrication to their customers. And it is also designed as a textbook. 'The correct lubricant' is a practical book with very little chemistry, theory and calculations. It is up to date including details of the new diesel engine oil specifications. The book will benefit anyone involved with the operation and maintenance of fleets and industrial plant and machinery in mining, manufacturing, construction, road works, trucking, transport and all other industries. There should be a hard copy of this book in every plant and fleet. A part of the package is a web page with more than 1500 links to relevant articles listed in line with the contents of the book. Read More325 downloads

22.05.2017This work demonstrates the importance of summit parameters for an anisotropic Gaussian rough surface. It is shown that lay direction may significantly affect the runningn wear process. Read More156 downloads

03.04.2017A script that solves the linear complementarity problem associated with the Boussinesq contact mechanics problem h = K*p+g, h'*p=0, h,p >=0, where the unknown h is the gap between two elastic (halfspace) bodies and the unknown p is the corresponding contact pressure. It can also be found at file exchange at the MATLAB Central Read More120 downloads

03.04.2017Matlab routines solving a linear complementarity problem appearing in lubrication with cavitation. Can also be found at the file exchange at MATLAB central. Read More119 downloads

29.03.2022TriboSolver (formerly known as Tribology Simulator) is a cloud based software for the simulation of the most common tribological problems: rough contact problem (pressure and subsurface stress calculations, deflections, stiffnesses), Elastohydrodynamic problem, Stribeck Curve simulation (calculation of friction in mixed lubricated contacts), calculation of contact temperatures in solids, wear and wear particles simulation and surface roughness evolution. You can find a guide on how to use TriboSolver here. The old version of TriboSolver can still be downloaded here. A manual can be found in the Help section. If you dont have MATLAB installed, you will need to install the MATLAB Compiler Runtime (MCR, free for download). See readme.txt file for further details. Solvers are based on the halfspace approximation theory for the contact, thermal and hydrodynamic simulations, which makes it faster compared to Finite Element Method or other fully numerical approaches. Read More2025 downloads

21.10.2016These mfiles calculate the adhesive parameters of the contact between 2 spheres based on the mechanical and geometrical properties of these 2 bodies and show the pressure distribution in such a contact. Read More221 downloads

30.07.2016A Matlab code (GUI) for calculation of friction coefficient in mixed lubricated conditions. Asperity based, including statistical (Greenwood and Williamson), deterministic models. Fully elastic and elasticplastic deformation regimes. Both point and line contact cases considered. Applicable to the contact with uniform film thickness (highly loaded). Moes fit is used to calculate central film thickness. Run stribeck_simulator.m. Read More609 downloads

23.06.2016The code plots the stress field along x direction due to a cuboid strain located in the center of coordinates system in an Infinite Space. The matlab file reproduces a plot from paper: "On the stress field due to initial strains in a cuboid Surrounded by an Inifinte Elastic Space", Chiu, 1977. It is useful in construction of 3D FFT based algorithm for calculation of elastic stress field due to initial strains (or residual, thermal, etc.). Read More93 downloads

21.11.2016A Matlab based line contact EHL solver with artificial diffusion for highly loaded cases. The degree of the diffusion is controlled. Fully coupled, differential deflection based numerical scheme. Finite difference discretization, central difference approximation of the pressure term and 2nd order backward difference approximation of the wedge term. Roelands pressureviscosity relation. It is designed for solving highly loaded cases. Newtons numerical solver is used. Launch run_numerical.m. Read More331 downloads

08.04.2016A Matlab based line contact EHL solver. Fully coupled, differential deflection based numerical scheme. Finite difference discretization, central difference approximation of the derivatives. Roelands pressureviscosity relation. It is optimized for lightly deforming contacts. Newtons numerical solver is used. Fast to converge, accurate solution. Launch run_numerical.m. Read More456 downloads

22.02.2016A Matlab code for calculation of a semianalytical solution of transient 1D Reynolds equation using Grubin's approximation. At first, the Reynolds equation is integrated analytically using Grubin's assumptions with respect to spatial coordinate and further numerically integrated with respect to temporal coordinate. Solution is then compared to the analytical Grubin’s solution for the central film thickness. Read More349 downloads

18.02.2016A Matlab code for calculation of a semianalytical solution of transient 1D Reynolds equation for rigidisoviscous case. At first, the Reynolds equation is integrated analytically with respect to spatial coordinate and further numerically integrated with respect to temporal coordinate. Solution is then compared to the analytical Martin’s solution for the central film thickness. Read More164 downloads

18.02.2016A Matlab file with the analytical solution of 1D Reynolds equation with possibility to specify the cavitation pressure. If cavitation pressure is set to atmosphere pressure, you get Martin’s solution. Derivation is also attached. Read More592 downloads

20.01.2022A simple matlab code for calculation of Hertz solution (Hertz model) for line, point and elliptical contacts. Also shows a plot of resultant pressure and deflection (not for elliptical contact). Here you can find an online tool: https://www.tribonet.org/calculators/hertzpressurecalculator/. Read More1218 downloads

18.02.2016Calculates central film thickness for line and point contacts using Moes fit. Read More175 downloads