Papers by Keyword: Contact Analysis

Abstract: In this article, with the help of modern methods of mechanics of a deformable body and the means of computer mathematics, the simulation of contact interaction of gears was performed. For contacting profiles outlined on the involute, the solution of the planar problem was implemented by using the ANSYS Workbench program. This paper compares gears with different tooth profile angles and considers the difference in the use of elastic and inelastic material in gearing. The obtained stress results are compared with results obtained by the AGMA standard. In conclusion, the results are shown in the comparative table.

Abstract: In order to improve the mechanical behaviour of bridge steel hoops, the plate shell finite element models of several steel hoops were established by using the general finite element software ABAQUS. Through changing the structural parameters of the stiffening plates, the influence of the stiffening plates on the mechanical properties of the steel hoops was explored. The calculation results show that the stress distribution at both ends of the steel hoop is uneven and there is a phenomenon of stress concentration. The spacing of stiffening plates has great influence on the mechanical properties of steel hoop. Some measures to improve the mechanical properties of steel hoop are given.

Abstract: This paper presents the analysis methods for design of automotive bumper covers. The bumper covers are plastic structures attached to the front and rear ends of an automobile and are expected to absorb energy in a minor collision. One requirement in design of the bumper covers is to minimize the bumper deflection within a limited range under specific loadings at specific locations based on the design guideline. To investigate the stiffness performance under various loading conditions, a numerical model based on the explicit dynamic finite element analysis (FEA) using the commercial FEA solver, LS-DYNA, is developed to analyze the design. The experimental tests are also carried out to verify the numerical model. The thickness of the bumper cover is a design variable which usually varies from 3 to 4 mm depending on locations. To improve the stiffness of the bumper, an optimal design for the bumper under a pre-defined loading condition is identified by using the topology optimization approach, which is an optimal design method to obtain the optimal layout of an initial design domain under specific boundary conditions. The outcome of this study provides an efficient and cost-effective method to predict and improve the design of automotive bumper covers.

Abstract: The proper selection of fixtures and its locations is necessary to avoid the dimensional and form inaccuracies that are developed due to elastic deformation of the workpiece during machining. It is necessary to predict the elastic deformation with higher precision in order to eliminate the above inaccuracies during the design of fixtures. In the present work, a Finite Element Method (FEM) based 3D contact analysis has been proposed to evaluate the elastic deformation of the workpiece under the influence of fixtures and machining forces. In the proposed model, workpiece has been considered as flexible body and fixture elements (locators and clamps) as rigid bodies. A new concept of pre-stressed harmonic analysis has been introduced in order to simulate the machining forces. The contact area of the locators has been considered using contact elements and the clamping forces as point forces. The model for the analysis is developed in ANSYS environment with suitable elements. The effect of material removal has also been considered in the analysis in view of obtaining more accurate and realistic results. The deformation of the workpiece has been predicted for a particular location of clamps, locators and machining forces and presented. It is possible to optimize the location of clamps and locators under the influence of machining forces, the above analysis is suggested.

Abstract: The contact fatigue life of gears has direct influences on the working life of the double-sided grinding machine, in the actual using process, the contact fatigue life of gears cannot meet the requirements of working because of many factors. This paper uses the finite element software ANSYS, establishs the two-dimensional model of gears, and analyzes and calculates it, the research shows that: life expectancy of gears is 2.13 years, so gears should have carburizing or carbonitriding heat treatment to fit process requirements, gears can live up to 5.82 years, it can fit the technological requirements of gear life of 5 years. It is some practical value for increasing the working life of the double-sided grinding machine and improving the stability and accuracy of the whole machine.

Abstract: Mechanical research on structural strength is done for the driving taper assembly of automobile in this paper, of which the assembly process is also explained. Based on theoretical analyses of the connection between tighten torque and axle force, the analytical model of the main reducer is established. In order to get the stress field and displacement field of the main reducer after assembly, which is used to conduct strength check, finite element analysis method is introduced. Based on these results, some theoretic suggestions for design and manufacture of the main reducer are provided.

Abstract: In order to search the pointing accuracy degradation and the wheel-rail contact of the National astronomical observatory 50m radio telescope, according to the actual wheel-rail structure and design indicators, the wheel rail contact problem with the finite element analysis based on non-Hertz rolling contact theory is analyzed. The results show that the maximum deformation should be less than 1 mm. Then the measurement scheme of rail horizontal error and deformation is formulated. The mean value of the rail horizontal error is 2.89mm, while the maximum rail horizontal error is 1.5mm. The rail maintenance scheme is put forward after the flaw detection which finds large areas of cracks at the rail junction and the welded joint. The measurement is taken after rail maintenance; the experimental data coincide with the simulation results and then verify the correctness of the wheel-rail contact model, also the solution scheme of rail cracks. The reason for the pointing accuracy degradation is verified finally, which also can provide an effective method for the wheel-rail design and maintenance of large radio telescope.

Abstract: FEM analysis of MSC. Marc program is used to simulate the models. Three-dimensional FEM model with contact analysis between deformable body of specimens and rigid body of load are studied. The isotropic material and The Von Mises yield criterion are used and kinematic hardening is used as a flow plasticity model. The effect of various shapes of loading tips is investigated. The load-displacement were established. The results of these works are expected to be a useful reference for analyzing structures under various shapes of loading tips either static or dynamic loading.

Abstract: The locomotive wheelset running with a high-speed, the wheels and axles of wheelset usually assembled by interference fit, the radial contact stress produced by interference cause the friction on the contact area, the axial force and torque of the wheelset transmitted by the friction. The value of prestress produced by the magnitude of interference change small in each load case, and it plays the main role in total stress of wheelset. So it’s very important that choosing a appropriate interference for the wheelset assembly base on the results solved by the finite element contact analysis.

Abstract: Based on the design of the large-scale shaking table test of an underground pipeline under three dimension seismic excitation, the dynamic response of the soil-structure is analyzed by using ANSYS. In the numerical simulation, Drucker-Prager constitutive model is adopted to simulate the soil, the interface between soil and pipeline are simulated with zero thickness contact elements, size effects of test box are diminished by defining viscoelastic boundary around soil, the acceleration time history curve of the original earthquake wave is compressed and processed according to using the model scale similarity and energy duration which is presented by Trifunac-Brady [1] , and then the characteristic of seismic response of the pipeline can be found. The results show that the top of pipeline is the seismic response intense regional, deformation displacements of the central areas at the bottom and top of pipeline are always larger than others, the entrance and exit are the weak positions of anti-seismic structure; moreover, the dynamic response and interactions of soil-pipeline in the model experiment can be more accurately simulated by the methods presented in the paper. Thus, it can be served as reference for the design and construction of subsurface structures.