The Hollow-Ended Roller—A Solution for Improving Fatigue Life in Asymmetrically Loaded Cylindrical Roller Bearings

1972 ◽  
Vol 94 (2) ◽  
pp. 153-162 ◽  
Author(s):  
W. J. Derner ◽  
R. A. Goodelle ◽  
L. E. Root ◽  
R. Rung
Keyword(s):  
Three Dimensional ◽  
Fatigue Tests ◽  
Hertzian Contact ◽  
Heavy Load ◽  
Roller Bearings ◽  
Equal Importance ◽  
Dimensional Finite Element ◽  
Hertzian Contact Stress ◽  
Three Dimensional Finite Element ◽  
Cylindrical Roller

To reduce the influence of misalignment (asymmetrical loading) on cylindrical roller bearings it is necessary to supplement the crown modifications of bearing elements. A unique hollow-ended roller design was developed for this purpose employing a three-dimensional finite element elasticity study to determine the stress state in the flexible rim section. The results when combined with the classical Hertzian contact stress distribution result in an accurate description of the shear stress field throughout the roller rim sections. Results of fatigue tests run under asymmetrically distributed loads supported the analytical efforts demonstrating significant improvements in L10 lives for the hollow-ended roller as compared to a solid roller. Peak stresses occurred in the vicinity of the contact area for both types of rollers with the solid exhibiting stresses 5 percent or more higher than those found in the hollow-ended type. Of equal importance, the observed failure mode for hollow-ended rollers under heavy load fatigue test conditions is one of conventional subsurface initiated O.D. spalling, thereby proving the rim design to be structurally sound.

Frictional Analysis of MoS2 Coated Ball Bearings: A Three-Dimensional Finite Element Analysis

1997 ◽  
Vol 119 (4) ◽  
pp. 754-763 ◽  
Author(s):  
M. R. Lovell ◽  
M. M. Khonsari ◽  
R. D. Marangoni
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Element Model ◽  
Hertzian Contact ◽  
Contact Theory ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Hertzian Contact Theory

A brief review of finite element contact and friction theory is presented for low-speed bearing operations. A three-dimensional finite element model is developed to realistically characterize the friction experienced by a coated ball bearing element. The finite elements results, which are obtained for various normal loads and ball materials, are verified using Hertzian contact theory and previous experimental tests performed by the authors. From the results, general trends for the frictional behavior of coated bearing surfaces are established and implications to the field of controls, as applied to precision positioning and tracking instruments are discussed.

Fatigue Behavior and Deformation of Aluminum and Steel HVOF Sprayed with WC-Co Coatings

1997 ◽  
Author(s):  
A. Ibrahim ◽  
C.C. Berndt
Keyword(s):  
Fatigue Life ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Three Dimensional ◽  
Element Model ◽  
Fatigue Tests ◽  
Dimensional Finite Element ◽  
Life Distributions ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Abstract The effect of WC-Co coating on the high cycle fatigue (HCF) behavior of SAE 12L14 steel and 2024-T4 aluminum was investigated. The fatigue tests were performed at room temperature and 370°C. The fatigue life distributions of specimens in the polished, grit blasted, peened, and coated conditions are presented as a function of the probability of failure. HVOF sprayed WC-Co coating has influenced the fatigue life of aluminum and steel. Factors contributing to this influence, which include grit blasting, elastic modulus, and residual stress, are discussed. A three-dimensional finite-element model (FEM) of the coated specimen was used to calculate the stress distribution across the coating and the substrate. The results of the analytical model are in good agreement with fatigue lives observed experimentally.

Contact stress variations near the insulated rail joints

2002 ◽  
Vol 216 (4) ◽  
pp. 265-273 ◽  
Author(s):  
Y. C. Chen ◽  
J. H. Kuang
Keyword(s):  
Contact Stress ◽  
Three Dimensional ◽  
Hertzian Contact ◽  
Stress Distributions ◽  
Linear Elastic ◽  
Contact Points ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Stress Variations ◽  
Contact Stress Distribution

The effect of an insulated rail joint (IRJ) on the contact stress variation near wheel-rail contact zones was simulated by employing three-dimensional finite element models. Three linear elastic IRJ materials, i.e. epoxy-fibreglass, polytetrafluoroethylene (PTFE) and Nylon-66, were investigated. Contact elements were used to simulate the interaction between the wheel and rail contact points. Numerical results showed that the presence of IRJ might significantly affect the wheel-rail contact stress distributions. Results also indicated that the traditional Hertzian contact theory is no longer available to predict the contact stress distribution around the rail joints.

Investigation of insert-hole interference fit influence on downhole drilling bit failure

2020 ◽  
Vol 234 (14) ◽  
pp. 1752-1761
Author(s):  
R Saeedi ◽  
MH Sadeghi
Keyword(s):  
Three Dimensional ◽  
Fatigue Tests ◽  
Hole Drilling ◽  
Interference Fit ◽  
Dimensional Finite Element ◽  
Manufacturing Tolerances ◽  
Three Dimensional Finite Element ◽  
Bit Life ◽  
Drilling Bit ◽  
Fitting Interference

Down-the-hole drilling is a reliable method for drilling in medium-to-hard geological structures. The insert-hole fitting interference value emerges as one of the most important factors of down-the-hole drilling bit life. In this study, fatigue tests were conducted using a tungsten carbide pin press-fitted into a hole in the specimens of DIN 1.6580 steel (which is used for manufacturing the bit body) to quantify the effect of interference value on the bit body failure. Then, the process of bit-rock collision was simulated using three-dimensional finite element method taking into account the residual stresses in the insert and bit body to determine the optimal interference value. Simulations were performed considering the rotary motion of the bit in addition to impact for a single-insert as well as a commercial 3.5 inch bit. Results showed that the interference value influences fatigue life significantly. Also, the velocity and angle of impact have considerable influence on body stresses. Results of this study can greatly assist the design of insert-hole manufacturing tolerances in down-the-hole bits.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Tire Modeling by Finite Elements

1992 ◽  
Vol 20 (1) ◽  
pp. 33-56 ◽  
Author(s):  
L. O. Faria ◽  
J. T. Oden ◽  
B. Yavari ◽  
W. W. Tworzydlo ◽  
J. M. Bass ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rolling Contact ◽  
Test Problems ◽  
State Behavior ◽  
Normal Contact ◽  
New Developments ◽  
Applied Torque ◽  
Dimensional Finite Element ◽  
Tire Modeling ◽  
Three Dimensional Finite Element

Abstract Recent advances in the development of a general three-dimensional finite element methodology for modeling large deformation steady state behavior of tire structures is presented. The new developments outlined here include the extension of the material modeling capabilities to include viscoelastic materials and a generalization of the formulation of the rolling contact problem to include special nonlinear constraints. These constraints include normal contact load, applied torque, and constant pressure-volume. Several new test problems and examples of tire analysis are presented.

Sign in / Sign up

Export Citation Format

Share Document