Internal Stresses in Elastohydrodynamic Lubrication of Rolling/Sliding Contacts

1989 ◽  
Vol 111 (1) ◽  
pp. 180-187 ◽  
Author(s):  
Farshid Sadeghi ◽  
Ping C. Sui

The internal stress distribution in elastohydrodynamic lubrication of rolling/sliding line contact was obtained. The technique involves the full EHD solution and the use of Lagrangian quadrature to obtain the internal stress distributions in the x, y, z-directions and the shear stress distribution as a function of the normal pressure and the friction force. The principal stresses and the maximum shear stress were calculated for dimensionless loads ranging from (2.0452 × 10−5) to (1.3 × 10−4) and dimensionless velocity of 10−10 to 10−11 for slip ratios ranging from 0 to pure sliding condition.

1969 ◽  
Vol 4 (4) ◽  
pp. 245-260 ◽  
Author(s):  
F A Khayyat ◽  
P R Lancaster

The paper describes some experiments to determine the stress distribution in rolls during the rolling of pure lead. The rolls were made from a hard transparent resin and the isochromatics and isoclinics were recorded whilst rolling was in progress. From these recordings the stress distributions were obtained. Particular reference was made to conditions of normal and shear stress at the contacting surfaces. The paper gives results for three roll diameters and for each of these four roll loads were applied. The experiments were carried out for both dry and lubricated conditions. The results of this work show a variation of the shear stress at the surface of contact accompanied by a change of sign at the neutral point. The normal roll-pressure curves are in general agreement with those found by workers using other techniques. The results also indicate a significant variation in the ratio (shear stress/normal pressure) over the contact surface, although this was decreased by lubrication. For a given roll load and diameter lubricated rolling, as opposed to dry rolling, increases the reduction but appears to have no effect on lateral spread. For a given roll load a decrease in roll diameter results in an increase in reduction, lateral spread, mean roll pressure, and friction.


1972 ◽  
Vol 39 (4) ◽  
pp. 1133-1136 ◽  
Author(s):  
V. K. Stokes

An attempt has been made to analyze asymmetric stress. Bounds for the principal stresses have been established in terms of the principal stresses corresponding to the symmetric part of the stress tensor. Sufficient conditions for the existence of one or three principal stresses have been established. Bounds have also been established for the maximum shear stress. Detailed results have been given for the case of a quasi two-dimensional stress distribution.


1958 ◽  
Vol 25 (2) ◽  
pp. 178-183
Author(s):  
A. J. Durelli ◽  
A. S. Kobayashi

Abstract The stress distributions around hydrostatically loaded circular holes in the neighborhood of corners was determined by using photoelasticity and brittle coatings. Photoelasticity (by means of a diffused-light polariscope) was used to determine the maximum shear lines (isochromatics), and brittle coatings were used to determine the directions of the principal stresses (isostatics). Tests were conducted for six plates with different ratios of hole radius to hole distance to the exterior boundary of plate (R/L). The results of these tests are presented in the form of curves. These curves show the distribution of the maximum shear stress along the diagonal of the plate, the maximum principal stress along the edges of the plate and of the hole, and the maximum shear stress along a perpendicular line to the exterior boundary drawn from the center of the hole. All these values are given as a function of R/L. Curves also are presented which compare the stresses on the diagonal of the plate at the boundary of the hole with the stresses computed using Lamé’s equation for a thick-walled cylinder. Comparisons also are made with the results obtained by Jeffery for a semi-infinite plate with a circular hole subjected to a hydrostatic pressure. All results are given in dimensionless form with the applied pressure as reference. The results published in this paper are new, but the techniques used have been described previously in papers by researchers from the Armour Research Foundation.


2018 ◽  
Vol 147 ◽  
pp. 01005
Author(s):  
Jonie Tanijaya

This study is carried out to evaluate the potential of three hybrid T-beams with web openings theoretical shear stresses distribution. The shear stresses at the opening edges were plotted at the working stage, yielding stage and collapse stage for these three tested beams. The available experimental results from the previous research was compared to the finite element results as well as the developed analytical. The shear stress distribution at the middle of the top and bottom chords of the opening in pure bending region are zero. At the upper and lower corners of the opening occurs the maximum shear stresses. The maximum shear stress occurs at the right lower corner chord at the high moment edge and at the left upper corner chord at the low moment edge in beams with openings at high shear and high flexural – shear region. Furthermore, an extensive parametric study is performed on these beams to find the distributing ratio of the shear force between the opening chords. The shear force at an opening in hybrid R/C T-beam is carried by the top and bottom chords of the opening according to the area – moment of inertia root ratio with the correction factor 0.70.


2013 ◽  
Vol 768-769 ◽  
pp. 351-357
Author(s):  
H. Sato ◽  
Y. Enomoto ◽  
K. Omote ◽  
S.I. Tanaka

Creep behavior of solid solution alloys are reasonably explained by concepts of the “internal and effective stress of high temperature deformation”. The internal stress is considered to be brought by formation of dislocation substructures, and the dislocation structures should have caused long range stress filed in interior of materials. Thus, residual stresses should also be brought by the same origin. In this paper, measurements of the residual stresses after creep deformation by 2D-Xray method are attempt, and the stresses are compared with so-called the “internal stress of high temperature deformation” measured by strain-dip stress-transient test. Although, the stress tensor depends on the deformation condition, the relation with the applied stress show complex manner at a glance. The maximum principal stresses, however, show relatively smaller than the applied stress, and fairly agree with that measured by strain-dip stress-transient technique. Importance of further considerations of the origin of so-called internal stresses is suggested.


2001 ◽  
Vol 123 (3) ◽  
pp. 268-273 ◽  
Author(s):  
Takenobu Takeda ◽  
Zhongchun Chen

In order to analyze the anisotropic hardening behavior of metals, an off-axis torsion test by combined loading is developed. In this test, the maximum shear stress direction φ can be changed from 0 deg to 90 deg while the ratio of maximum and minimum principal stresses is kept at −1. With increasing angle φ, the yield stress of the torsional-prestrained steel decreases; the difference between the directions of the maximum shear stress and principal shear strain increment rises to a maximum value and then decreases. It is experimentally verified that anisotropy is more severe when a smaller offset strain is used in defining the yield stress.


2010 ◽  
Vol 431-432 ◽  
pp. 98-101
Author(s):  
Jia Jing Yuan ◽  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Feng Xu

The contact stress of cemented carbide with NCD coating in elastic contact was analyzed using ANSYS. Factors such as elastic modulus and thickness of NCD film and elastic modulus of interlayer which affect the shear stress distribution of NCD film on cemented carbide substrate were investigated. The results show that the maximum shear stress point moves towards the interface with the increase of film elastic modulus. Film thickness has a significant effect on shear stress distribution of NCD film. High shear stress develops in the film layer with the increase of film thickness. Interlayer with low elastic modulus will cause shear stress concentration in NCD film.


2022 ◽  
Vol 2148 (1) ◽  
pp. 012025
Author(s):  
J Wang ◽  
J Liu ◽  
Y Q Fu

Abstract In view of the influence of Joint Roughness Coefficient (JRC), which is for quantitative description of the joint surface roughness, on the stress field of the rock mass, compression test and shear-compression test were simulated on models with different joint roughness. The photoelasticity technique is applied to examine the feasibility of numerical simulation. The results show that numerical simulation results are in agreement with the results of photoelastic experiments. The stress concentration area is distributed near the joint plane. Thus, the joint plane controls the shear strength of the rock. In compression test, the maximum shear stress of the model is proportional to JRC and the normal pressure. In shear-compression test, when the ratio of the axial shear to the normal pressure is small, the maximum shear stress is nonlinearly positively correlated with JRC. When the ratio of the axial shear to the normal pressure is relatively large, the relationship curve between the maximum shear stress and JRC is parabolic. When the JRC is small, as the ratio of the axial shear force to the normal pressure increases, the maximum shear stress changes abruptly, and the maximum shear stress after the mutation decreases significantly. The reason is that the upper and lower parts of the model have slipped, resulting in a redistribution of stress. In addition, when the JRC is 6 to 12, it is more likely to cause stress concentration.


1944 ◽  
Vol 11 (4) ◽  
pp. A235-A239
Author(s):  
N. J. Hoff

Abstract The stresses in the sheet covering, stringers, and rings of a reinforced monocoque cylinder of circular cross section are calculated for the case of a loading consisting of concentrated symmetric forces applied to the rings in the planes of the rings. The conventional assumptions of a linear normal stress distribution and a corresponding shear-stress distribution in the bent cylinder are replaced by a least-work analysis. Application of the theory to the numerical example of a cantilever monocoque cylinder yields a maximum shear stress in the sheet covering and a maximum bending moment in the ring amounting to 900 per cent and 33 per cent, respectively, of the values obtained by the conventional analysis.


2007 ◽  
Vol 353-358 ◽  
pp. 389-391 ◽  
Author(s):  
Li Xin Dong ◽  
Guang Ze Dai ◽  
Xian Feng Zhou ◽  
L.L. Liu ◽  
Qing Qing Ni

The model of slub-like short fibers reinforced composites is suggested from the viewpoint of bamboo in the nature and patterns characteristic of simulated silk PET used in textile industry. The stress distributions in the enlarged-end fiber and in the matrix are analyzed. The axial stress in the fiber and matrix is found to increase and the interfacial shear stress decrease with the radius of the enlarged end.


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