The effects of point-contact pressure on silicon planar junctions

1965 ◽  
Vol 53 (6) ◽  
pp. 618-619 ◽  
Author(s):  
K.E. Preece ◽  
P.R. Selway
Keyword(s):  
Contact Pressure ◽  
Point Contact

scholarly journals EFFECTS OF DESIGN PARAMETERS ON STATIC EQUIVALENT STRESS OF RADIAL ROLLING BEARINGS

2021 ◽  
Vol 61 (1) ◽  
pp. 163-173
Author(s):  
Mehmet Bozca
Keyword(s):  
Contact Pressure ◽  
Contact Area ◽  
Elasticity Modulus ◽  
Equivalent Stress ◽  
Point Contact ◽  
Design Parameters ◽  
Line Contact ◽  
Rolling Bearings ◽  
Von Mises ◽  
Maximum Contact

The aim of this study is to theoretically investigate the effects of design parameters on the static equivalent stress of radial rolling bearings, such as the point contact case for ball bearings and line contact case for roller bearings. The contact pressure, contact area and von Misses stress of bearings are calculated based on geometrical parameters, material parameters and loading parameters by using the developed MATLAB program. To achieve this aim, both the maximum contact pressure pmax and Von Mises effective stress σVM are simulated with respect to design parameters such as varying ball and roller element diameters and varying ball and roller element elasticity modulus. For the point contact case and line contact case, it was concluded that increasing the diameter of ball and roller elements results in reducing the maximum contact pressure pmax Furthermore, increasing the elasticity modulus of the ball and roller elements results in increasing the maximum contact pressure σVM. Furthermore, increasing the elasticity modulus of the ball and roller element results in increasing the maximum contact pressure pmax and Von Mises effective stress σVM because of the decrease of contact area A. The determination of the diameter of the ball and roller elements and the selection of material are crucial and play an effective role during the design process. Therefore, bearing designers and manufacturers should make the bearing geometrical dimensions as large as possible and bearing material as elastic as possible. Furthermore, the stress-based static failure theory can also be used instead of the standard static load carrying capacity calculation. Moreover, Von Mises stress theory is also compatible with the finite element method.

Pressure Calculation From Experimentally Evaluated Lubricant Thickness Within EHL Contacts

2007 ◽  
Author(s):  
M. Vrbka ◽  
M. Vaverka ◽  
R. Poliscuk ◽  
I. Krupka ◽  
M. Hartl
Keyword(s):  
Film Thickness ◽  
Contact Pressure ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Lubricant Film ◽  
Solution Technique ◽  
Lubricant Film Thickness ◽  
Smooth Contact ◽  
Friction Surfaces

This paper is concerned with elastohydrodynamic lubrication, especially determination of lubricant film thickness and contact pressure within a point contact of friction surfaces of machine parts. A new solution technique for numerical determination of contact pressure is introduced. Direct measurement of contact pressure is very difficult. Hence, input data of lubricant film thickness obtained from the experiment based on colorimetric interferometry are used for calculation of pressure using the inverse elasticity theory. The algorithm is enhanced by convolution in order to increase calculation speed. The approach gives credible results on smooth contact and it is currently extended to enable the study of contact of friction surfaces with dents.

Four-Point Contact Ball Bearing Model With Deformable Rings

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Samy Lacroix ◽  
Daniel Nélias ◽  
Alexandre Leblanc
Keyword(s):  
Contact Pressure ◽  
Ball Bearing ◽  
Point Contact ◽  
Contact Angles ◽  
Structural Deformation ◽  
Geometrical Parameters ◽  
Fe Model ◽  
The Impact ◽  
Maximum Contact ◽  
Contact Ellipse

In many applications, such as four-point contact slewing bearings or main shaft angular contact ball bearings, the rings and housings are so thin that the assumption of rigid rings does not hold anymore. In this paper, several methods are proposed to account for the flexibility of rings in a quasi-static ball bearing numerical model. The modeling approach consists of coupling a semianalytical approach and a finite element (FE) model to describe the deformation of the rings and housings. The manner in which this weak coupling is made differs depending on how the structural deformation of the ring and housing assemblies is injected into the set of nonlinear geometrical and equilibrium equations in order to solve them. These methods enable us to account for ring ovalization, ring twist, and raceway opening (including change of conformity) since a tulip deformation mode of the ring groove is observed for high contact angles. Either the torus fitting technique or mean displacement computation are used to determine these geometrical parameters. A comparison between the different approaches allows us to study, in particular, the impact of raceway conformity change. The loads used in this investigation are chosen in order that the maximum contact pressure (the Hertz pressure) at the ball-raceway interface remains below 2000 MPa, without any contact ellipse truncation. For the ball bearing example considered here, relative differences of up to 30% on the axial displacement, 10% on the maximum contact pressure, and 10% on the contact angle are observed by comparing rigid and deformable rings for a typical loading representative of the one encountered in operation. Despite the local change of conformity, which becomes significant at high contact angles and for thin ball bearing flanges, it is shown that this hardly affects the internal load distribution. The paper ends with a discussion on how the ring and housing flexibility may affect the loading envelope when the truncation of the contact ellipse is an issue.

Stress Analysis of Asymmetric Spur Face-Gear Pair Based on Finite Element Method

2013 ◽  
Vol 483 ◽  
pp. 309-314
Author(s):  
Ning Zhao ◽  
Meng Qi Zhang ◽  
Hui Guo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Pressure ◽  
Point Contact ◽  
Element Model ◽  
Face Gear ◽  
Single Tooth ◽  
Gear Geometry ◽  
Tooth Pair ◽  
Element Method

According to the theory of gear geometry, the equations of teeth surface of double pressure angles asymmetric face-gear were conducted. Discrete points were generated in MATLAB according to the surface equations, and then the author established contact finite element models of single-tooth pair in ANSYS. The calculated value of contact pressure of the single tooth contact finite element model and the calculated value of contact pressure which given by the point-contact Hertz theory were compared to verify the effectiveness of the contact finite element method. Several groups of parameters were calculated and the results showed that the use of reasonable asymmetric design can effectively reduce the max surface contact pressure and the max tooth root bending stress.

FEA of a Double-Point Contact Elastomeric Gasket Considering Corrosion of Counterparts and Tilting during Assembly

2017 ◽  
Vol 739 ◽  
pp. 241-246
Author(s):  
Tae Hyung Kim ◽  
Eun Min Park ◽  
Tae Hyun Kim
Keyword(s):  
Contact Pressure ◽  
Double Point ◽  
Single Point ◽  
Point Contact ◽  
Operating Conditions ◽  
The Novel ◽  
Element Analysis ◽  
Rubber Material ◽  
Sealing Performance ◽  
Discrete Contact

The novel geometry of a gasket’s cross-section to optimize the sealing performance was proposed in spite of corrosion of its counterparts or tilted assembly. EPDM was applied for the rubber material and the sealing performance including stress, strain and contact pressure was estimated by finite element analysis (FEA) in both cased of normal and tilted assemblies. If the gaskets were to be normally assembled in the grooves, both gaskets (single-point contact and double-point contact) could be utilized for sealing systems. Even at the tilted assembly, the double-point contact gasket showed two discrete contact pressure areas; thus it could maintain its sealing performance over time at various operating conditions, compared to the single-point gasket.

Maximum Interlabial Pressures in Normal Speakers

1997 ◽  
Vol 40 (2) ◽  
pp. 400-404 ◽  
Author(s):  
Virginia A. Hinton ◽  
Winston M. C. Arokiasamy
Keyword(s):  
Speech Production ◽  
Contact Pressure ◽  
Direct Evidence ◽  
Unit Area ◽  
Jaw Movement ◽  
Contractile Forces ◽  
Contact Pressures ◽  
Muscle Contractile

It has been hypothesized that typical speech movements do not involve large muscular forces and that normal speakers use less than 20% of the maximum orofacial muscle contractile forces that are available (e.g., Amerman, 1993; Barlow & Abbs, 1984; Barlow & Netsell, 1986; DePaul & Brooks, 1993). However, no direct evidence for this hypothesis has been provided. This study investigated the percentage of maximum interlabial contact pressures (force per unit area) typically used during speech production. The primary conclusion of this study is that normal speakers typically use less than 20% of the available interlabial contact pressure, whether or not the jaw contributes to bilabial closure. Production of the phone [p] at conversational rate and intensity generated an average of 10.56% of maximum available interlabial pressure (MILP) when jaw movement was not restricted and 14.62% when jaw movement was eliminated.

Point-contact spectroscopy of quasi-1D conductors with CDW

1999 ◽  
Vol 09 (PR10) ◽  
pp. Pr10-179-Pr10-181
Author(s):  
A. A. Sinchenko ◽  
Yu. I. Latyshev ◽  
S. G. Zybtsev ◽  
I. G. Gorllova
Keyword(s):  
Point Contact ◽  
Point Contact Spectroscopy

Rim Slip and Bead Fitment of Tires: Analysis and Design2

2006 ◽  
Vol 34 (1) ◽  
pp. 38-63 ◽  
Author(s):  
C. Lee
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Frictional Torque ◽  
Finite Element Analyses ◽  
Inflation Pressure ◽  
Contact Pressure Distribution ◽  
Design Modification ◽  
Iterative Design ◽  
Slip Resistance ◽  
Braking Torque

Abstract A tire slips circumferentially on the rim when subjected to a driving or braking torque greater than the maximum tire-rim frictional torque. The balance of the tire-rim assembly achieved with weight attachment at certain circumferential locations in tire mounting is then lost, and vibration or adverse effects on handling may result when the tire is rolled. Bead fitment refers to the fit between a tire and its rim, and in particular, to whether a gap exists between the two. Rim slip resistance, or the maximum tire-rim frictional torque, is the integral of the product of contact pressure, friction coefficient, and the distance to the wheel center over the entire tire-rim interface. Analytical solutions and finite element analyses were used to study the dependence of the contact pressure distribution on tire design and operating attributes such as mold ring profile, bead bundle construction and diameter, and inflation pressure, etc. The tire-rim contact pressure distribution consists of two parts. The pressure on the ledge and the flange, respectively, comes primarily from tire-rim interference and inflation. Relative contributions of the two to the total rim slip resistance vary with tire types, depending on the magnitudes of ledge interference and inflation pressure. Based on the analyses, general guidelines are established for bead design modification to improve rim slip resistance and mountability, and to reduce the sensitivity to manufacturing variability. An iterative design and analysis procedure is also developed to improve bead fitment.

Finite Element Simulation of Tire-Rim Interface

1989 ◽  
Vol 17 (4) ◽  
pp. 305-325 ◽  
Author(s):  
N. T. Tseng ◽  
R. G. Pelle ◽  
J. P. Chang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Simulation ◽  
Contact Pressure ◽  
Element Model ◽  
Experimental Measurements ◽  
Inflation Pressure ◽  
Interference Fit ◽  
Element Simulation ◽  
Rubber Composite

Abstract A finite element model was developed to simulate the tire-rim interface. Elastomers were modeled by nonlinear incompressible elements, whereas plies were simulated by cord-rubber composite elements. Gap elements were used to simulate the opening between tire and rim at zero inflation pressure. This opening closed when the inflation pressure was increased gradually. The predicted distribution of contact pressure at the tire-rim interface agreed very well with the available experimental measurements. Several variations of the tire-rim interference fit were analyzed.

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