Modeling of Finite-Length Line Contact Problem With Consideration of Two Free-End Surfaces

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Haibo Zhang ◽  
Wenzhong Wang ◽  
Shengguang Zhang ◽  
Ziqiang Zhao

Finite-length line contact conditions, existing in applications such as gears or roller bearings, lead to subsurface stress distribution influenced by the free boundaries. This paper presents a semi-analytical method (SAM) for the finite-length line contact problem, based on the overlapping concept and matrix formation, to consider the effect of two free-end surfaces. In order to obtain two free surfaces, three half-spaces with mirrored loads to be solved are overlapped to cancel out the stresses at expected surfaces. The error introduced by this method is analyzed and proven to be negligible. The conjugate gradient method (CGM) is used to solve the pressure distribution, and the fast Fourier transform (FFT) is used to speed up the elastic deformation and stress-related calculation. The model is verified by finite element method (FEM) and shows a high conformity and efficiency. Besides, the line contact situations are discussed to explore the effect of free surfaces.

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Haibo Zhang ◽  
Wenzhong Wang ◽  
Shengguang Zhang ◽  
Ziqiang Zhao

Elastohydrodynamic lubrication (EHL) analysis in finite line contacts is usually modeled by a finite-length roller contacting with a half-space, which ignores effect of the two free boundaries existing in many applications such as gears or roller bearings. This paper presents a semi-analytical method, involving the overlapping method and matrix formation, for EHL analysis in the finite line contact problem to consider the effect of two free end surfaces. Three half-spaces with mirrored loads to be solved are overlapped to cancel out the stresses at expected surfaces, and three matrices can be obtained and reused for the same finite-length space. The isothermal Reynolds equation is solved to obtain the pressure distribution and the fast Fourier transform (FFT) is used to speed up the elastic deformation and stress related calculation. Different line contact situations, including straight rollers, tapered rollers, and Lundberg profile rollers, are discussed to explore the effect of free end surfaces.


2017 ◽  
Vol 899 ◽  
pp. 272-277
Author(s):  
Hugo Dutra Gomes ◽  
Maria Carolina dos Santos Freitas ◽  
Luciano Pessanha Moreira ◽  
Flavia de Paula Vitoretti ◽  
Jose Adilson de Castro

The present study is primarily engaged in the implementation of the incremental stamping process in a computerized numeric control This paper presents two different approaches to this forming process, an experimental and other numerical. Experimental used by the computer numerical control to perform the printing process and performs numerical simulations of the process using the finite element method. Some parameters are analyzed in both approaches, such as product geometry effects, tool geometry, tool speed, tool path, contact conditions and mechanical properties of the materials.


2010 ◽  
Vol 152-153 ◽  
pp. 279-283
Author(s):  
Run Bo Bai ◽  
Fu Sheng Liu ◽  
Zong Mei Xu

Contact problem, which exists widely in mechanical engineering, civil engineering, manufacturing engineering, etc., is an extremely complicated nonlinear problem. It is usually solved by the finite element method. Unlike with the traditional finite element method, it is necessary to set up contact elements for the contact analysis. In the different types of contact elements, the Goodman joint elements, which cover the surface of contacted bodies with zero thickness, are widely used. However, there are some debates on the characteristics of the attached elements of the Goodman joint elements. For that this paper studies the type, matching, and meshing of the attached elements. The results from this paper would be helpful for the finite element contact analysis.


2016 ◽  
Vol 33 (4) ◽  
pp. 1033-1050 ◽  
Author(s):  
Xin Zhao ◽  
Zili Li

Purpose – The purpose of this paper is to develop a numerical approach to solve the transient rolling contact problem with the consideration of velocity dependent friction. Design/methodology/approach – A three dimensional (3D) transient FE model is developed in elasticity by the explicit finite element method. Contact solutions with a velocity dependent friction law are compared in detail to those with the Coulomb’s friction law (i.e. a constant coefficient of friction). Findings – The FE solutions confirm the negligible influence of the dependence on the normal contact. Hence, analysis is focussed on the tangential solutions under different friction exploitation levels. In the trailing part of the contact patch where micro-slip occurs, very high-frequency oscillations are excited in the tangential plane by the velocity dependent friction. This is similar to the non-uniform sliding or tangential oscillations observed in sliding contact. Consequently, the micro-slip distribution varies greatly with time. However, the surface shear stress distribution is quite stable at different instants, even though it significantly changes with the employed friction model. Originality/value – This paper proposes an approach to solve the transient rolling contact problem with the consideration of velocity dependent friction. Such a problem was usually solved in the literature by the simplified contact algorithms, with which detailed contact solutions could not be obtained, or with the assumption of steady rolling.


Author(s):  
Ichiro Moriwaki ◽  
Tomohito Tani ◽  
Toshiro Miyata ◽  
Akio Ueda ◽  
Masayoshi Yoshihara

A new finite element analysis for meshing gear pair has been developed with a new element called “tooth flank film element.” The new element is a phantom element put on a tooth flank without any thickness, and enables boundary conditions for a contact problem in meshing teeth to be easily dealt with. In the present paper, contact stresses between tooth flanks of mating gear pair calculated with the proposed finite element method are compared with stresses measured with pressure measurement films. As a result, the proposed method was confirmed to be useful for evaluation of contact stress.


2012 ◽  
Vol 184-185 ◽  
pp. 188-195
Author(s):  
Jun Jie Zhao ◽  
Hong Qi Tian ◽  
Yue Qing Ren ◽  
Zhai Jun Lu

Conventional drive wheel strength check is based on Hertz line contact theory to do the calculation, for security reasons, the design is more conservative,so that there is a certain margin in carrying capacity of the wheel. To address the above issues, this paper analyzes the wheel contact problem for a precise non-linear contact by the finite element method. By comparison of two methods, it verifies that using the finite element is reasonable to deal with these issues, while it provides a reference for the rational design of full load capacity wheels as well.


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