High Precision Contact Model for Ball Bearings With Waviness

Mapping Intimacies ◽

10.1115/detc2021-67056 ◽

2021 ◽

Author(s):

Camille Jeannot ◽

E. Sadoulet-Reboul ◽

S. Dufrenoy

Keyword(s):

High Precision ◽

Predictive Models ◽

Angular Position ◽

Contact Model ◽

Ball Bearings ◽

Nonlinear Contact ◽

Tangential Forces ◽

Bearing Behavior ◽

Global Parameters

Abstract Studying high precision ball bearings requires the development of predictive models. In presence of waviness on the rings, geometrical and also mechanical parameters will vary according to the angular position. To consider these modifications, a nonlinear contact model is proposed with normal and tangential forces calculation using Hertz and Dahl’s models. To solve the static equilibrium of the bearing, a highly modular energy method is developed. It allows the determination of both local and global parameters using the same equation. The 2D developed approach can be used to study different waviness orders and magnitudes to get a better understanding on how this affects the bearing behavior (contact load, balls gaping, pointing defects...). The presented results show that even small contact direction reorientation can create tangential forces. This modifies the bearing deflections and induces a residual moment. These phenomena can only be observed when the contact is accurately modeled.

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On effects of non-systematic reflections on weak-beam images of partial dislocations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087756 ◽

1991 ◽

Vol 49 ◽

pp. 688-689

Author(s):

K. Z. Botros ◽

S. S. Sheinin

Keyword(s):

High Precision ◽

Stacking Fault ◽

Important Application ◽

Stacking Fault Energy ◽

Sharp Peak ◽

Weak Beam ◽

Partial Dislocations ◽

Deviation Parameter ◽

Beam Diffraction

The main features of weak beam images of dislocations were first described by Cockayne et al. using calculations of intensity profiles based on the kinematical and two beam dynamical theories. The feature of weak beam images which is of particular interest in this investigation is that intensity profiles exhibit a sharp peak located at a position very close to the position of the dislocation in the crystal. This property of weak beam images of dislocations has an important application in the determination of stacking fault energy of crystals. This can easily be done since the separation of the partial dislocations bounding a stacking fault ribbon can be measured with high precision, assuming of course that the weak beam relationship between the positions of the image and the dislocation is valid. In order to carry out measurements such as these in practice the specimen must be tilted to "good" weak beam diffraction conditions, which implies utilizing high values of the deviation parameter Sg.

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Comparative assessment of informational content of the equations of F.P. Hadlock and the computer program of V.N. Demidov in determination of term of gestation and fetal weight in the III trimester of gestation

10.21516/2413-1458-2017-16-2-145-150 ◽

2017 ◽

Author(s):

E.A. Derkach , O.I. Guseva

Keyword(s):

Computer Program ◽

High Precision ◽

Gestational Age ◽

Computer Programs ◽

Comparative Assessment ◽

Fetal Weight ◽

Informational Content ◽

Third Trimester ◽

The Third

Objectives: to compare the accuracy of equations F.P. Hadlock and computer programs by V.N. Demidov in determining gestational age and fetal weight in the third trimester of gestation. Materials: 328 patients in terms 36–42 weeks of gestation are examined. Ultrasonography was performed in 0–5 days prior to childbirth. Results: it is established that the average mistake in determination of term of pregnancy when using the equation of F.P. Hadlock made 12,5 days, the computer program of V.N. Demidov – 4,4 days (distinction 2,8 times). The mistake within 4 days, when using the equation of F.P. Hadlock has met on average in 23,1 % of observations, the computer program of V.N. Demidov — 65,9 % (difference in 2,9 times). The mistake more than 10 days, took place respectively in 51,7 and 8,2 % (distinction by 6,3 times). At a comparative assessment of size of a mistake in determination of fetal mass it is established that when using the equation of F.P. Hadlock it has averaged 281,0 g, at application of the computer program of V.N. Demidov — 182,5 g (distinction of 54 %). The small mistake in the mass of a fetus which isn't exceeding 200 g at application of the equation of F.P. Hadlock has met in 48,1 % of cases and the computer program of V.N. Demidov — 64,0 % (distinction of 33,1 %). The mistake exceeding 500 g has been stated in 18 % (F.P. Hadlock) and 4,3 % (V.N. Demidov) respectively (distinction 4,2 times). Conclusions: the computer program of V.N. Demidov has high precision in determination of term of a gestation and mass of a fetus in the III pregnancy.

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Determination of electron backscattering coefficient of beryllium by a high-precision Monte Carlo simulation

Nuclear Materials and Energy ◽

10.1016/j.nme.2020.100862 ◽

2021 ◽

Vol 26 ◽

pp. 100862

Author(s):

Abrar Hussain ◽

Lihao Yang ◽

Shifeng Mao ◽

Bo Da ◽

Károly Tőkési ◽

...

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

High Precision ◽

Backscattering Coefficient ◽

Electron Backscattering

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A High-Precision Absolute Angular Position Sensor With Vernier Capacitive Arrays Based on Time Grating

IEEE Sensors Journal ◽

10.1109/jsen.2019.2921479 ◽

2019 ◽

Vol 19 (19) ◽

pp. 8626-8634 ◽

Cited By ~ 4

Author(s):

Hongji Pu ◽

Hewen Wang ◽

Xiaokang Liu ◽

Zhicheng Yu ◽

Kai Peng

Keyword(s):

High Precision ◽

Angular Position ◽

Position Sensor

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Using anisotropic dispersive materials for high-precision determination of the energy of charged particles

Technical Physics Letters ◽

10.1134/s1063785009030201 ◽

2009 ◽

Vol 35 (3) ◽

pp. 263-266 ◽

Cited By ~ 5

Author(s):

A. V. Tyukhtin

Keyword(s):

High Precision ◽

Charged Particles ◽

Precision Determination ◽

High Precision Determination

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The Determination of the Three-Point Support Design of Machine Tool Based on iSIGHT

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.607.342 ◽

2014 ◽

Vol 607 ◽

pp. 342-345

Author(s):

Sheng Hui Zhao ◽

Xiao Chuang Zhu ◽

Da Wei Zhang

Keyword(s):

Machine Tool ◽

High Precision ◽

Multidisciplinary Optimization ◽

Joint Surface ◽

Objective Functions ◽

Multi Objective Optimization ◽

Support Design ◽

Optimal Position ◽

Point Support

In order to meet the requirements of high-precision machine tool, it has been an important factor to select an appropriate way to support the bed. By building a multidisciplinary optimization (MDO) process based on iSIGHT, this article select the deformation difference of the guides and the deformation difference of the joint surface between column and bed of the machine tool as the objective functions, and then conduct a multi-objective optimization (MOO) of the positional parameters of the three-point support. Eventually the optimization result is given and the optimal position of the three-point support is determined.

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Fast determination of calcium concentration in the internal tissues of a single seed using laser-induced breakdown spectroscopy

Analytical Methods ◽

10.1039/c6ay01028h ◽

2016 ◽

Vol 8 (37) ◽

pp. 6705-6710 ◽

Cited By ~ 3

Author(s):

Pengcheng Han ◽

Daming Dong ◽

Xiaofan Du ◽

Leizi Jiao ◽

Xiande Zhao

Keyword(s):

High Precision ◽

Calcium Concentration ◽

Seed Vigor ◽

Laser Induced Breakdown Spectroscopy ◽

Fast Determination ◽

Breakdown Spectroscopy ◽

Single Seed ◽

Small Influence ◽

Laser Induced Breakdown

Laser-induced breakdown spectroscopy was used for the fast determination of calcium concentration in the internal tissues of a single seed. Compared with conventional methods, LIBS had obvious advantages, such as a little analysis spot, little ablation, high precision, and small influence on the seed vigor.

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