The Effect of Oil Supply on Cage and Roller Motion in a Lubricated Roller Bearing

1970 ◽  
Vol 92 (1) ◽  
pp. 39-51 ◽  
Author(s):  
R. J. Boness
Keyword(s):  
Theoretical Analysis ◽  
Experimental Evidence ◽  
Roller Bearing ◽  
Operating Conditions ◽  
Experimental Results ◽  
Hydrodynamic Conditions ◽  
Oil Supply ◽  
Minimum Value ◽  
Theoretical Results

Experimental results indicate that oil supply can have a significant effect on cage and roller motion in a lubricated roller bearing. A theoretical analysis is presented which enables cage and roller motion, for various operating conditions, to be predicted. The theoretical results imply that reducing the oil supply to a minimum value required to maintain full hydrodynamic conditions, reduces cage slip by up to 75 percent of its fully flooded value. This conclusion is consistent with existing experimental evidence.

ANALYSIS OF SURFACE ROUGHNESS AT OVERLAPPING LASER SHOCK PEENING

2016 ◽  
Vol 23 (03) ◽  
pp. 1650012 ◽  
Author(s):  
F. Z. DAI ◽  
Z. D. ZHANG ◽  
J. Z. ZHOU ◽  
J. Z. LU ◽  
Y. K. ZHANG
Keyword(s):  
Surface Roughness ◽  
Theoretical Analysis ◽  
Equilateral Triangle ◽  
Experimental Results ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Minimum Value ◽  
Maximum Value ◽  
Shock Peening ◽  
Iso 25178

The overlapping effects on surface roughness are studied when samples are treated by laser shock peening (LSP). Surface roughness of overlapped circular laser spot is calculated by ISO 25178 height parameters. The usually used overlapping styles namely isosceles-right-triangle-style (AAP) and equilateral-triangle-style (AAA) are carefully investigated when the overlapping degree in x-axis ([Formula: see text]) is below 50%. Surface roughness of isosceles-right-triangle-style attains its minimum value at [Formula: see text] of 29.3%, and attains its maximum value at [Formula: see text] of 43.6%. Surface roughness of equilateral-triangle-style attains its minimum value at [Formula: see text] of 42.3%, and attains its maximum value at [Formula: see text] of 32%. Experimental results are well consistent with theoretical analysis.

scholarly journals Experimental analysis of bolts employed as shear connectors in circular concrete-filled tube columns

2019 ◽  
Vol 12 (2) ◽  
pp. 337-370 ◽  
Author(s):  
E. M. XAVIER ◽  
J. G. R. NETO ◽  
A. M. C. SARMANHO ◽  
L. ROQUETE ◽  
L. G. C. De PAULA
Keyword(s):  
Theoretical Analysis ◽  
Experimental Analysis ◽  
Load Capacity ◽  
Concrete Strength ◽  
Steel Tube ◽  
Experimental Results ◽  
Shear Connectors ◽  
Concrete Confinement ◽  
Push Out ◽  
Theoretical Results

Abstract This paper presents experimental and theoretical analysis of bolts employed as shear connectors in circular concrete-filled steel tube columns (CFTs). The theoretical results, obtained from ABNT NBR 16239:2013 formulations, were compared with the experimental results. A series of push-out tests were carried out, where the diameter and length of the bolts, the number of connectors and the concrete strength were varied. From the experimental results, it was observed that the equations from ABNT NBR 16239:2013 are conservative. Therefore, it is proposed an adjustment to the formulations in order to consider the concrete confinement. It was also verified that increments in the diameter and the length of the bolt increase the load capacity of the connector. However, the variation of the quantity of bolts and the concrete strength did not interfere in the load capacity.

Effect of Objective Normalization and Penalty Parameter on Penalty Boundary Intersection Decomposition-Based Evolutionary Many-Objective Optimization Algorithms

2020 ◽  
pp. 1-30
Author(s):  
Lei Chen ◽  
Kalyanmoy Deb ◽  
Hai-Lin Liu ◽  
Qingfu Zhang
Keyword(s):  
Theoretical Analysis ◽  
Experimental Results ◽  
Decomposition Algorithms ◽  
Theoretical Studies ◽  
Distance Metrics ◽  
Penalty Parameter ◽  
True Nature ◽  
Normalization Strategy ◽  
Normalization Process ◽  
Theoretical Results

An objective normalization strategy is essential in any evolutionary multiobjective or many-objective optimization (EMO or EMaO) algorithm, due to the distance calculations between objective vectors required to compute diversity and convergence of population members. For the decomposition-based EMO/EMaO algorithms involving the Penalty Boundary Intersection (PBI) metric, normalization is an important matter due to the computation of two distance metrics. In this article, we make a theoretical analysis of the effect of instabilities in the normalization process on the performance of PBI-based MOEA/D and a proposed PBI-based NSGA-III procedure. Although the effect is well recognized in the literature, few theoretical studies have been done so far to understand its true nature and the choice of a suitable penalty parameter value for an arbitrary problem. The developed theoretical results have been corroborated with extensive experimental results on three to 15-objective convex and non-convex instances of DTLZ and WFG problems. The article, makes important theoretical conclusions on PBI-based decomposition algorithms derived from the study.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

scholarly journals A Synopsis Based Approach for Itemset Frequency Estimation over Massive Multi-Transaction Stream

2021 ◽  
Vol 16 (2) ◽  
pp. 1-30
Author(s):  
Guangtao Wang ◽  
Gao Cong ◽  
Ying Zhang ◽  
Zhen Hai ◽  
Jieping Ye
Keyword(s):  
Frequency Estimation ◽  
Frequent Itemsets ◽  
Frequent Itemset ◽  
Experimental Results ◽  
Closure Property ◽  
Frequent Itemset Mining ◽  
Itemset Mining ◽  
Minimum Value ◽  
Downward Closure ◽  
Bounded Size

The streams where multiple transactions are associated with the same key are prevalent in practice, e.g., a customer has multiple shopping records arriving at different time. Itemset frequency estimation on such streams is very challenging since sampling based methods, such as the popularly used reservoir sampling, cannot be used. In this article, we propose a novel k -Minimum Value (KMV) synopsis based method to estimate the frequency of itemsets over multi-transaction streams. First, we extract the KMV synopses for each item from the stream. Then, we propose a novel estimator to estimate the frequency of an itemset over the KMV synopses. Comparing to the existing estimator, our method is not only more accurate and efficient to calculate but also follows the downward-closure property. These properties enable the incorporation of our new estimator with existing frequent itemset mining (FIM) algorithm (e.g., FP-Growth) to mine frequent itemsets over multi-transaction streams. To demonstrate this, we implement a KMV synopsis based FIM algorithm by integrating our estimator into existing FIM algorithms, and we prove it is capable of guaranteeing the accuracy of FIM with a bounded size of KMV synopsis. Experimental results on massive streams show our estimator can significantly improve on the accuracy for both estimating itemset frequency and FIM compared to the existing estimators.

Applications of vibro-acoustic measurement and analysis in conjunction with tribological parameters to assess surface fatigue wear developed in the roller-bearing system

2021 ◽  
pp. 135065012098246
Author(s):  
Shashikant Pandey ◽  
Muniyappa Amarnath
Keyword(s):  
Roller Bearing ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Stribeck Curve ◽  
Fatigue Wear ◽  
Surface Fatigue ◽  
Rolling Element ◽  
Measurement And Analysis ◽  
Contact Surfaces ◽  
Bearing System

Rolling-element bearings are the most commonly used components in all rotating machinery. The variations in the operating conditions such as an increase in the number of operating cycles, load, speed, service temperature, and lubricant degradation result in the development of various defects such as pitting, spalling, scuffing, scoring, etc. The defects that appeared on rolling contact surfaces cause surface deterioration and change in the vibration and sound levels of the bearing system. The present experimental investigations are aimed at assessing the surface fatigue wear that appears on the contact surfaces of roller bearings. The studies considered the estimation of specific film thickness, analysis of surface fatigue wear developed on the rolling-element surfaces, surface roughness analysis, grease degradation analysis using Fourier transform infrared radiation, and vibration and sound signal measurement and analysis. The results obtained from the experimental investigation provide a good correlation between surface wear, vibration, and sound signals with a transition in the lubrication regimes in the Stribeck curve.

A Comparison of Theoretical and Experimental Results From Spherical Shells With a Single Radially Attached Nozzle

1967 ◽  
Vol 89 (3) ◽  
pp. 333-338 ◽  
Author(s):  
F. J. Witt ◽  
R. C. Gwaltney ◽  
R. L. Maxwell ◽  
R. W. Holland
Keyword(s):  
Spherical Shell ◽  
Internal Pressure ◽  
Experimental Results ◽  
Strain Gages ◽  
Spherical Shells ◽  
Axial Thrust ◽  
Outside Diameter ◽  
Theoretical Results

A series of steel models having single nozzles radially and nonradially attached to a spherical shell is presently being examined by means of strain gages. Parameters being studied are nozzle dimensions, length of internal nozzle protrusions, and angles of attachment. The loads are internal pressure and axial thrust and moment loadings on the nozzle. This paper presents both experimental and theoretical results from six of the configurations having radially attached nozzles for which the sphere dimensions are equal and the outside diameter of the attached nozzle is constant. In some instances the nozzle protrudes through the vessel.

scholarly journals Self-Governance in Generalized Exchange. A Laboratory Experiment on the Structural Embeddedness of Peer Punishment

Games ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 50
Author(s):  
Georg Kanitsar
Keyword(s):  
Laboratory Experiment ◽  
Public Good ◽  
Experimental Evidence ◽  
Experimental Results ◽  
Social Cooperation ◽  
The Public ◽  
Norm Enforcement ◽  
Structural Setting ◽  
Structural Embeddedness ◽  
Generalized Exchange

Peer punishment is widely lauded as a decentralized solution to the problem of social cooperation. However, experimental evidence of its effectiveness primarily stems from public good structures. This paper explores peer punishment in another structural setting: a system of generalized exchange. In a laboratory experiment, a repeated four-player prisoner’s dilemma is arranged either in a public good structure or in a circular network of generalized exchange. The experimental results demonstrate that the merits of peer punishment do not extend to generalized exchange. In the public good, peer punishment was primarily altruistic, was sensitive to costs, and promoted cooperation. In generalized exchange, peer punishment was also altruistic and relatively frequent, but did not increase cooperation. While the dense punishment network underlying the public good facilitates norm enforcement, generalized exchange decreases control over norm violators and reduces the capacity of peer punishment. I conclude that generalized exchange systems require stronger forms of punishment to sustain social cooperation.

scholarly journals Three doors anomaly, “should I stay, or should I go”: an artefactual field experiment

2021 ◽  
Author(s):  
Andrea Morone ◽  
Rocco Caferra ◽  
Alessia Casamassima ◽  
Alessandro Cascavilla ◽  
Paola Tiranzoni
Keyword(s):  
Field Experiment ◽  
Experimental Evidence ◽  
Bayesian Updating ◽  
Anomalous Behavior ◽  
Status Quo ◽  
Experimental Results ◽  
Illusion Of Control ◽  
Optimal Decision ◽  
Status Quo Bias ◽  
The Impact

AbstractThis work aims to identify and quantify the biases behind the anomalous behavior of people when they deal with the Three Doors dilemma, which is a really simple but counterintuitive game. Carrying out an artefactual field experiment and proposing eight different treatments to isolate the anomalies, we provide new interesting experimental evidence on the reasons why subjects fail to take the optimal decision. According to the experimental results, we are able to quantify the size and the impact of three main biases that explain the anomalous behavior of participants: Bayesian updating, illusion of control and status quo bias.

Litigation Spending and Care under the English and American Rules: Experimental Evidence

2021 ◽  
Author(s):  
Baptiste Massenot ◽  
Maria Maraki ◽  
Christian Thöni
Keyword(s):  
Experimental Evidence ◽  
Rent Seeking ◽  
Experimental Results ◽  
Settlement Rate ◽  
Levels Of Care ◽  
Personal Cost

Abstract We investigate the effects of fee-shifting in an experimental litigation game. In our setup, a defendant may cause harm to a plaintiff. The defendant can take precautions to lower the probability of harm at a personal cost. In case of harm, the parties go to court, where the winner is determined by a rent-seeking contest. We compare two fee-shifting rules: under the American rule each party bears its own litigation costs; under the English rule the loser has to reimburse the winner’s expenses. We test the hypothesis that the English rule leads to higher litigation spending but also to higher care compared to the American rule. The experimental results largely support the predictions: fee-shifting leads to higher litigation spending, which motivates higher levels of care. When the parties are offered the possibility to settle their dispute out of court, fee-shifting leads to even higher litigation spending in court, but it neither affects the settlement rate nor care.

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