Optimization of the Anode-Stub Contact: Effect of Casting Temperature, Contact Stress, Temperature and Surface Roughness

2013 ◽  
pp. 1353-1357 ◽  
Author(s):  
Bjarte Oye ◽  
Anne Store ◽  
Elin Haugland ◽  
Jorund Hop
Keyword(s):  
Surface Roughness ◽  
Contact Stress ◽  
Casting Temperature ◽  
Contact Effect

Tubing String Thread Sealing Surfaces Damage Evaluation Based on Acoustic Elasticity Theory

2019 ◽  
Vol 944 ◽  
pp. 828-834 ◽  
Author(s):  
Jian Jun Wang ◽  
Jian Hua Sun ◽  
Shang Yu Yang ◽  
Yao Rong Feng ◽  
Kai Lin
Keyword(s):  
Surface Roughness ◽  
Elasticity Theory ◽  
Contact Stress ◽  
Surface Characterization ◽  
Surface Damage ◽  
Center Frequency ◽  
Sealing Performance ◽  
Tubing String ◽  
Acoustic Elasticity

During the processing of tubing premium threaded made up, the degree of the thread sealing surface intactness will directly affect the sealing performance of the string. Nevertheless, there are some difficulties to detect the damage of the engaged sealing surface effectively. In the present study the sealing surface damage was judged by the sealing surface contact stress’s relative changes according to the acoustic elasticity theory,. At the same time, the wear defects generated at the tubing sealing surface, during the tubing made up, contrasted with the wear and unworn surface roughness of coupling ultrasonic detected about the sealing surface. The results showed that with the acoustic amplitude evaluated the sealing contact stress was susceptible to the influence of surface roughness of coupling. But the reflection wave with the center frequency on the sealing surface characterization of the contact stress could avoid this problem effectively.

Influence of Contact Stress, Sliding Velocity, and Surface Roughness on the Sliding Wear of a Composite Restorative

1981 ◽  
Vol 60 (5) ◽  
pp. 914-918 ◽  
Author(s):  
William F. Bailey ◽  
Stephen L. Rice ◽  
Ronald J. Albert ◽  
Samuel C. Temin
Keyword(s):  
Surface Roughness ◽  
Contact Stress ◽  
Sliding Wear ◽  
Sliding Velocity

Contact Stress Between Rollers With Surface Irregularity

1981 ◽  
Vol 103 (2) ◽  
pp. 492-498 ◽  
Author(s):  
A. Kubo ◽  
T. Okamoto ◽  
N. Kurokawa
Keyword(s):  
Surface Roughness ◽  
Stress Concentration ◽  
Contact Stress ◽  
Surface Irregularity ◽  
Maximum Surface ◽  
Surface Durability

To obtain fundamental data for research on surface durability of contacting bodies, contact stress between rollers with surface roughness or pit is analyzed. The increasing degree of contact stress owing to surface roughness is given by a non-dimensional factor, which is the ratio between maximum surface roughness and geometrical interpenetration of the contacting bodies. The contact stress concentration around a triangular pit is also discussed.

Surface Roughness and Stress Responses of a Feldspar Porcelain to Fatigue Impact

2010 ◽  
Vol 443 ◽  
pp. 557-561
Author(s):  
Richard Lymer ◽  
Ling Yin ◽  
Zhong Xiao Peng ◽  
Robert H.B. Jones ◽  
Andrew Sandham
Keyword(s):  
Surface Roughness ◽  
Contact Stress ◽  
Stress Responses ◽  
Average Surface Roughness ◽  
Dental Ceramics ◽  
Restorative Dentistry ◽  
Grinding Forces ◽  
Load Range ◽  
Human Teeth ◽  
Average Surface

Dental ceramics are attractive in restorative dentistry due to their approximations to the appearances and functions of human teeth with which we chew our food. Chewing processes generally occur at cyclic loading range of 70–800 N and up to 1400 cycles per day. Most fatigue studies on dental ceramics were conducted at the loads up to 250 N. These loads are much smaller than the maximum bite forces of 500–700 N and tooth clench or grinding forces of up to 800 N. This paper reports on an investigation of fatigue response of a dental porcelain at the higher end of the load range impacted by a tungsten carbide ball. The responses of surface roughness and contact stress to the applied loads and cyclic numbers were quantitatively studied. The results show that the cyclic numbers had significant influences on both average surface roughness Ra and maximum roughness Rmax (ANOVA, p<0.05). However, the applied loads did not significantly affect Ra and Rmax values (ANOVA, p>0.05). It is also found that the contact stress significantly reduced with the cycles (ANOVA, p<0.05) but did not show a significant change with the applied loads (ANOVA, p>0.05).

Contact Stress and Contact Width Analysis of Corrugated Metal Gasket

2015 ◽  
Vol 799-800 ◽  
pp. 765-769 ◽  
Author(s):  
Didik Nurhadiyanto ◽  
Shigeyuki Haruyama ◽  
Ken Kaminishi ◽  
I Made Gatot Karohika ◽  
Dan Mujiyono
Keyword(s):  
Surface Roughness ◽  
Contact Stress ◽  
Simulation Analysis ◽  
Design Parameters ◽  
The Real ◽  
Real Contact ◽  
Contact Width ◽  
Simulation And Experiment ◽  
Corrugated Metal ◽  
Important Design

Previous studies on corrugated metal gaskets have established that the contact width, contact stress, and surface roughness are important design parameters for optimizing gasket performance. However, the contact stress and contact width considering the surface roughness when the leakage occur did not defined yet. In this study, we determined the real contact stress and contact width when leakage started on 25A-size metal gasket. The contact width determined through a comparison between simulation and experimental results. The contact stress determined through a simulation analysis. The experiment involves a helium leakage test using new metal gaskets having different surface roughness levels. The result justified that the real contact width and average contact stress when the leakage started occur were 0.195mm and 800MPa, respectively. There is a good agreement for contact width both by simulation and experiment result. The contact width for flange having surface roughness 1.5μm is longest than the others.

Micropitting Generation Mechanism for Gears

2008 ◽  
Vol 2 (5) ◽  
pp. 341-347
Author(s):  
Nobuyoshi Yoshida ◽  
◽  
Tokihiko Taki
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Contact Stress ◽  
Contact Area ◽  
Maximum Stress ◽  
Real Contact Area ◽  
Durability Test ◽  
Metallic Contact ◽  
Real Contact ◽  
Surface Durability

To determine the mechanism behind micropitting, we measured micropit shape occurring in surface durability test, based on the real contact area size formed by asperity interaction in surface roughness. Individual micropitting within surface roughness asperity does not exceed asperity size. Micropitting occurs due to contact stress increased by a high friction coefficient due to metallic contact. Stress analysis showed that maximum stress causes micropitting.

A Critical Examination of the Elastohydrodynamic Criterion for the Scoring of Gears

1974 ◽  
Vol 96 (3) ◽  
pp. 418-422 ◽  
Author(s):  
E. F. Finkin ◽  
A. Gu ◽  
L. Yung
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Film Thickness ◽  
Contact Stress ◽  
Thermal Effects ◽  
Critical Examination ◽  
Computational Techniques ◽  
Hertz Contact ◽  
Gear Mesh

A critical examination is made of the concept that gear scoring occurs when the EHD film thickness is less than several times the combined surface roughness. The well known experimental data of Borsoff, Borsoff and Godet, and Ku and Baber is analyzed using advanced EHD computational techniques. The study finds: (a) Gear scoring occurs under fully boundary-lubricated conditions and not even close to the breakdown of the EHD film. (b) Isothermal calculations of minimum EHD film thickness are in error both in magnitude and in trend with failure velocity. An analysis which takes thermal effects into account must be used. (c) Pitch point EHD film thickness does not reliably represent minimum EHD film thickness and therefore cannot be substituted for it. (d) The peak Hertz contact stress in a gear mesh may be significantly understated if calculated only at the pitch point.

Roughness measurements of nonlinear optical polymer films by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 22-23
Author(s):  
I. H. Musselman ◽  
R.-T. Chen ◽  
P. E. Russell
Keyword(s):  
Surface Roughness ◽  
Scanning Tunneling Microscopy ◽  
Nonlinear Optical ◽  
Polymer Surface ◽  
Light Extinction ◽  
Scanning Tunneling ◽  
Silicon Substrates ◽  
Tunneling Microscopy ◽  
Optical Polymer ◽  
Total Light

Scanning tunneling microscopy (STM) has been used to characterize the surface roughness of nonlinear optical (NLO) polymers. A review of STM of polymer surfaces is included in this volume. The NLO polymers are instrumental in the development of electrooptical waveguide devices, the most fundamental of which is the modulator. The most common modulator design is the Mach Zehnder interferometer, in which the input light is split into two legs and then recombined into a common output within the two dimensional waveguide. A π phase retardation, resulting in total light extinction at the output of the interferometer, can be achieved by changing the refractive index of one leg with respect to the other using the electrooptic effect. For best device performance, it is essential that the NLO polymer exhibit minimal surface roughness in order to reduce light scattering. Scanning tunneling microscopy, with its high lateral and vertical resolution, is capable of quantifying the NLO polymer surface roughness induced by processing. Results are presented below in which STM was used to measure the surface roughness of films produced by spin-coating NLO-active polymers onto silicon substrates.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

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