Once you have built your vehicle and track models in simpack rail, the contact results are evaluated automatically. As anthony said, learn about hertz contact stress before you try and run an analysis. The software calculates hertzian contact stress and the subsurface stressen of the general contact of two elliptical bodies according to the hertzian theorie. For contact stress analysis hertzian equation is used and for. It uses a color function to visualize the contact zone between a statically loaded pair of contact models, a sphere and a torus. Pdf hertz contact stress analysis and validation using. This paper presents a study by the finite element method fem of the contact tensions between two bodies and the results obtained are compared with the calculations obtained on basis of the relations of the theory of h.
The distribution of stress on the teeth for couple and pinion in case of nonshifted gear mechanism are shown in figure 5. Applicability of the hertz contact theory to rolling rubber. The analysis of the contact type of the bearing is presented below. Dec 06, 2016 hertz contact theory hct is a study of contact stress and deformation which is widely used in many engineering fields. Hertzian contact of a cylinder and a sphere, steuermann contact of.
After hertz s work, people do a lot of study on the stresses arising from the contact between two elastic bodies. Im currently using an evaluation license of ansys workbench 14. The cylindrical and cubic element are in line contact as can be seen on the picture below. The student community is a public forum for authorized ansys academic product users to share ideas and ask questions. In this video, i have talked about the way in which the analysis is to be done of a cylinder being compressed between two rectangular plates in ansys. Using hertz contact formula i calculated contact stress for cylinder in contact with cylinderical socket but i dont know to which stress to compare this contact stress. They have created model in ansys design modeler and analysis is done using ansys software. I am not familiar with the different kinds of contacts in ansys, since i am just.
Dec 12, 2014 in this video, i have talked about the way in which the analysis is to be done of a cylinder being compressed between two rectangular plates in ansys. Contact stress analysis of spur gear for different materials using ansys and hertz equation putti srinivasa rao1, nadipalli sriraj2, mohammad farookh2 1professor, dept. I found that the contact pressure is reported to be zero for a bonded contact and. Structural analysis software fea analysis ansys structural. Applicability of the hertz contact theory to rolling. The aim is to find the contact stress between rail and wheel. Actually, i believe you will have to include the wheels in the analysis. Modeling hertzian stress in line contact by cilinder and plate.
The same window then immediately displays the results. Frictional contact with augmented langrange and pure penalty gives better results of contact stresses than. Using specialized software for finite element analysis cosmos, ansys, nice, pro. Use of contact pair in ansys hertzian stresses on contact. Some time ago i have had a similar problem in calculating contact hertz stress in algor. The results which are obtained by solving the general equation of motion in ansys software are given in table 4. I am trying to model hertz contact stress for a cylinder on a plane, but my fea pressure is less than a factor of 17 when. Oct 10, 2018 the student community is a public forum for authorized ansys academic product users to share ideas and ask questions. I dont find the wikepedia article very illuminating. In general machines are designed with a set of elements to reduce cost, ease of assembly and manufacturability etc. International journal for research in applied science. It can be used to calculate mechanical point and line contact dimensions and material stresses. A finite element model will sometimes contain a socalled singularity.
In case of hertzian contact are obtained precise information regarding the state of deformation at the contact level, it can. It uses special target and nodetosurface contact elements. With its detailed, stepbystep explanations, and extensive worked examples and sample problems, this book will develop readers understanding of fea and their ability to use ansys software. In another failure mode, called contact or hertzian fatigue, repeated stresses cause surface cracks and detachment of metal fragments from the tooth contact surface. Cut the half circles vertically into quarter circles. Contact stress predicted by using hertzian analytical method. A new version of the software for calculation of hertzian contact stress is available. For one of my fea assignments, i have to model the hertzian contact stress in two cylindrical elements that the student community is a public forum for authorized ansys academic product users to share ideas and ask questions. The hertzian contact stress calculations give the contactstress that is induced in flawless steels no inclusions, when the contactforce is constant across the cam and camfollower see also contact assumptions, below. Jan 24, 2012 i have calculated a static contact stress of 670 nmm2 using formula from mechanical engineering design, shigley, 5th edition. The analysis properties were changed from 3d to 2d and geometry was created in designmolder. To generate the profile of spur gear teeth and calculate of gear bending stress using lewis equation and hence check the feasibility of modified gear profile.
This means there are points in your model where values tend toward an infinite value. Abstract the contact stress and bending stress in mating gears is the key parameter in gear design. The software has a set of basic assumptions to optimizing design or studying the effect of variations of manufacturing conditions on shape, size, deformation, and stress in the contact zone. We can also do wear analysis due to frictional rubbing between the contact surfaces. The study of contact pressure analyses and prediction of. Lab 8 geometry creation hertzian contact create the geometry in the ansys dm or the cad software of your choice. Modeling hertzian contact stress in line contact by two cylinders. Nicholas lecain, tutorial of hertzian contact stress analysis, opti 521, college of optical sciences, university. Procedia engineering 38 2012 264 a 269 18777058 a 2012 published by elsevier ltd. A clearly laidout window allows you to enter material properties, dimensions and loads. Hertz contact stress calculations and graphs with hertzwin.
Hertz contact stress calculations hertzwin is a free hertzian contact stress calculator. The distribution of stress on the teeth for couple and pinion in case. The hertzian contact stress calculations give the contact stress that is induced in flawless steels no inclusions, when the contact force is constant across the cam and camfollower see also contact assumptions, below. Contact stress analysis of a roller conveyor irjet.
Maximum tooth root stress and hertzian contact stress for each solution is calculated. Hertzian contact between two spheres simscale documentation. Hertz contact stress analysis and validation using finite. Contact stress distribution of large diameter ball bearing. You just select the wheels and moments in time that are the most interesting and off you go. Comparison of bending stress analysis has been performed for symmetric and asymmetric spur gear tooth at critical section. One also needs to address stress issues at the contact regions between any two elements, stress is induced when a load is applied to two elastic solids in contact. With catia, the parametric modeling at the interface of the roller and pallet is carried out. Hertzian contact stress wolfram demonstrations project. The hertz contact stress usually refers to the stress close to the area of contact between two spheres of different radii. New version of hertzian contact stress calculation mesys ag.
Twodimensional contact stress engineering analysis with ansys software. Contact stress and bending stress analysis of spur gear by. That is the only way to get reasonably accurate results. The results of the theor etical stress values are compared with the stress values from the finite element analysis. This kind of stress may not be significant most of the time, but may cause. The meshes used in a and c were created with the automatictetrahedralization meshing algorithm on the simscale platform. The application performs all calculations automatically. A vibration model of ball bearings with a localized defect. For an electronic copy pdf of the relevant report, click here consider a simple problem that illustrates a comparison between the analytical and numerical results.
It simply did not support contact stress calculations. Hertzian contact stress refers to the localized stresses that develop as two curved surfaces come in contact and deform slightly under the imposed loads. In the development phase, the contact stress analysis is carried out. Modeling hertzian contact stress in line contact by two. Keywords hertz contact stress, contact fe analysis, stresses within rollers, roller contact analysis. The hertzian equation is used to calculate the contact stress. Then the desired quantities stress, strain, dof can be plotted from the solution. My problems lies that there is no acceptance criteria. Contact stress analysis of spur gear for different materials.
Defect model based on the hertzian contact stress distribution 3. Contact stress analysis of spur gear for different. Hertz contact vm272 in ansyss verification manual analysis in ansys. I decided to try to do a hertz contact stress problem of a rod in a veegroove using 2d plane stress idealization and symmetry. The model is a simplified model of a train wheel on the rail. Dec 26, 2014 in general machines are designed with a set of elements to reduce cost, ease of assembly and manufacturability etc. Hertz contact stress is very localized, so you dont need a full cylinder, a half cylinder will do. Therefore, the aim of this study is to present the effect of rotational speed of gear on contact stress and comparison between the finite element numerical. It gives the contact stress as a function of the normal contact force. Hertzwin is a free hertzian contact stress calculator. The maximum shear stress obtained from ansys is 268. Gear tooth surface wear involves removal or displacement of material due to mechanical, chemical or electrical action.
This research was carried out with the help of finite element analysis which could have been. Barrel coupling is modelled using catiav5 software. The project aims at the minimization of both contact. Investigation of the effects of profile shift in helical. High stresses are generated in this case as the total load acts through this line of contact. With the finite element analysis fea solvers available in the suite, you can customize and automate solutions for your structural mechanics problems and parameterize them to analyze multiple design scenarios. In workbench, change the analysis type of the geometry cell to 2d. Apr 22, 20 step by step procedure of how to do static structural analysis of hertzian contact analysis ansys workbench. Hertz contact theory hct is a study of contact stress and deformation which is widely used in many engineering fields. According to the instructions in the ansys help 27, the actual contact stress should be the summation of the above two stress, so the maximum contact pressure is, and. Easy simulation for fatigue analysis in ansys aim ansys blog. Feb 11, 2008 hertzian contact stress refers to the localized stresses that develop as two curved surfaces come in contact and deform slightly under the imposed loads.
This amount of deformation is dependent on the elasticity of the the material in contact, i. I found a nice paper giving the theoretical solution for a 2d plane strain problem here. Does contact pressure in ansys mechanical represent pressure at. Hertz contact stress analysis and validation using finite element analysis. Contact stresses finite element analysis fea engineering. This paper present the contact stress analysis and bending stress analysis of spur gear by analytical method. A contact patch is generated at this line of contact. Step by step procedure of how to do static structural analysis of hertzian contact analysis ansys workbench. They compared fea analysis results with hertz contact equation for the materials grey cast iron and steel. Line to solid face contact simutech group ansys fea. In figure 4, when a ball contacts the raceway, the contact is a point contact if the load is zero, as shown in figure 4a. The issue is once more to model the hertzian contact stress in a rigid cylindrical element, pushing down on a flexible plate of the same material.
Ansys, on the other hand gave me good correlation between fea results of contact stress and expected theoretical values for typical cases. The results of the theor etical stress values are compared with. These contact stresses are called hertz contact stresses, which was first studies by hertz in 1881. Its shape is an ellipse as expected from a hertzian contact model. Ansys structural analysis software enables you to solve complex structural engineering problems and make better, faster design decisions. This page provides a free online calculation for hertzian contact stress for point and line contact including a diagram for subsurface stresses. If you are a newbie to finite element analysis, you might assume that a singularity is a t. However, there are many limiting conditions for the applications of the hct, in this paper, the contact model between a plastic cylinder and a rubber cylinder does not fit two limiting conditions. Contact stress analysis of spur gear under the different. The ansys code offers stress analysts a variety of contact element options. For one of my fea assignments, i have to model the hertzian contact stress in two cylindrical elements that. The kalker contact addon is a version of contact that is integrated seamlessly into simpack rail. Pdf contact stress analysis in wheelrail by hertzian.
Procedure for this project, the solution was done in stages. Hertz contact stress is very localized, so you dont need a full cylinder, a half. Introduction when there are two nonconforming surfaces that come into contact the point or line of contact can be a location. This demonstration presents the hertzian contact stress distribution and elastic deformations. Mech designer is perfectly capable of calculating the hertzian contact stress. Ansys workbench tutorial video beginnerexpert contact non linear frictional fe analysis. Tutorial hertz contact stress university of arizona. Ansys allows us to import geometries or to make them from within ansys, apply loading and constraints, and then solve for a solution. It was found that stress was more than the correct value of contact stress obtaining from approximating tools. Introduction when there are two nonconforming surfaces that come into contact the point or line of contact can be a location of very high stress values.
The software has large sequences of randomly modified principal radii of curvature of the contacting surfaces. Result obtained in hertz stress calculator software in hertz stress calculator the data assumed for calculation provided as input for calculating contact stress is shown in fig. Investigation of the effects of profile shift in helical gear. Safety and economy of railway traffic is enormously influenced by the contact stress variation caused by wheel rail contact profile changes. Contact stresses are predicted using ansys software by adopting different types of contact algorithms and contact types. The simulation results of simscale were compared to the results presented in ssnv104. Tutorial hertz contact stress brian taylor opti521 fall 2016, sid. Tutorial on hertz contact stress university of arizona. That creates a new face to hold onto on the bottom and to push on the top. They have concluded that stress values of steel and grey cast iron gear are comparable. The material of both wheel and rail is steel and the friction coefficient is 0. Recent versions of ansys workbench mechanical include detection of contact between line bodies and faces.
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