Frictional Performance of Pavements and Estimates of Accident Probability

2009 ◽  
pp. 73-73-25 ◽  
Author(s):  
JL Burchett ◽  
RL Rizenbergs
Keyword(s):  
Accident Probability ◽  
Frictional Performance

FRICTIONAL PERFORMANCE OF DIMPLED TEXTURED SURFACES ON A FRICTIONAL PAIR: AN EXPERIMENTAL STUDY

2018 ◽  
Vol 8 (4) ◽  
pp. 18 ◽  
Author(s):  
G. VIGNESH ◽  
M. PRAKASH ◽  
SELVAM MILON D. ◽  
P. RAGUPATHI ◽  
◽  
...  
Keyword(s):  
Experimental Study ◽  
Frictional Pair ◽  
Textured Surfaces ◽  
Frictional Performance

scholarly journals Fast laser surface texturing of spherical samples to improve the frictional performance of elasto-hydrodynamic lubricated contacts

Friction ◽  
2021 ◽  
Author(s):  
G. Boidi ◽  
P. G. Grützmacher ◽  
A. Kadiric ◽  
F. J. Profito ◽  
I. F. Machado ◽  
...  
Keyword(s):  
Surface Texturing ◽  
Hydrodynamic Pressure ◽  
Friction Reduction ◽  
Laser Surface Texturing ◽  
Textured Surfaces ◽  
Engineering Applications ◽  
Lubricated Contacts ◽  
Fluid Uptake ◽  
Direct Laser ◽  
Frictional Performance

AbstractTextured surfaces offer the potential to promote friction and wear reduction by increasing the hydrodynamic pressure, fluid uptake, or acting as oil or debris reservoirs. However, texturing techniques often require additional manufacturing steps and costs, thus frequently being not economically feasible for real engineering applications. This experimental study aims at applying a fast laser texturing technique on curved surfaces for obtaining superior tribological performances. A femtosecond pulsed laser (Ti:Sapphire) and direct laser interference patterning (with a solid-state Nd:YAG laser) were used for manufacturing dimple and groove patterns on curved steel surfaces (ball samples). Tribological tests were carried out under elasto-hydrodynamic lubricated contact conditions varying slide-roll ratio using a ball-on-disk configuration. Furthermore, a specific interferometry technique for rough surfaces was used to measure the film thickness of smooth and textured surfaces. Smooth steel samples were used to obtain data for the reference surface. The results showed that dimples promoted friction reduction (up to 20%) compared to the reference smooth specimens, whereas grooves generally caused less beneficial or detrimental effects. In addition, dimples promoted the formation of full film lubrication conditions at lower speeds. This study demonstrates how fast texturing techniques could potentially be used for improving the tribological performance of bearings as well as other mechanical components utilised in several engineering applications.

How do Optimistic Individuals Affect Insurance Advertisements?

2020 ◽  
Vol 14 (2) ◽  
Author(s):  
Yoichiro Fujii ◽  
Michiko Ogaku ◽  
Mahito Okura ◽  
Yusuke Osaki
Keyword(s):  
Maximum Level ◽  
Optimal Level ◽  
Insurance Premium ◽  
Free Rider ◽  
Free Rider Problem ◽  
Accident Probability ◽  
Insurance Firms ◽  
The Difference ◽  
Accident Probabilities ◽  
Equilibrium Number

AbstractSome people have optimistic expectations regarding their accident probability, and thus, refrain from purchasing adequate insurance. This study investigates how insurance firms use advertisements to lower the ratio of optimistic individuals in the market. The main results are as follows: first, the optimal level of advertisements is maximized when the insurance premium is moderate. Second, the maximum level of advertisement varies according to the degree of optimism, which is measured by the difference between accurate and optimistic accident probabilities. Third, the advertisement decision is affected by the free-rider problem, and the equilibrium number of insurance firms with advertisement is always larger than that of firms without advertisement in a competitive insurance market.

Thermal/frictional performance of spiral pipe with ring-shape depression used as in-pond heat exchanger

Solar Energy ◽  
2021 ◽  
Vol 224 ◽  
pp. 742-756
Author(s):  
Yan Cao ◽  
Hamdi Ayed ◽  
Mehran Hashemian ◽  
Alibek Issakhov ◽  
Makatar Wae-hayee
Keyword(s):  
Heat Exchanger ◽  
Ring Shape ◽  
Frictional Performance

The analyses of frictional losses and thermal stresses in a diesel engine piston coated with different thicknesses of thermal barrier films using co-simulation method

2021 ◽  
pp. 146808742110656
Author(s):  
Fatma Bayata ◽  
Cengiz Yildiz
Keyword(s):  
Diesel Engine ◽  
Coating Thickness ◽  
Thermal Stresses ◽  
Equivalent Stress ◽  
Simulation Method ◽  
Thermal Barrier ◽  
Barrier Films ◽  
Engine Piston ◽  
Frictional Performance ◽  
Artificial Neural Network Ann

This study comparatively presents the thermal and mechanical effects of different Thermal Barrier Coatings (TBCs) and their thicknesses on the performance of aluminum diesel engine piston by combining Finite Element Analyses (FEA) and Artificial Neural Network (ANN) methods. The piston structure of MWM TbRHS 518S indirect injection six-cylinder diesel engine was modeled. The clustered TBCs (NiCrAlY–Gd2Zr2O7, NiCrAlY–MgO-ZrO2, NiCrAl–Yttria Partially Stabilized Zirconia (YPSZ), and NiCrAlY–La2Zr2O7) were implemented to the related surface of aluminum alloy piston and then static, thermal, and transient structural FEA were conducted for each model. Based on both of the temperature and equivalent stress distributions, NiCrAlY–Gd2Zr2O7 coated model displayed the best performance. Additionally, the effects of top coating thicknesses of TBCs were investigated in the range of 0.1–1.0 mm with 0.1 mm increments in FEAs. The thermally effective top coating thickness was predicted as 0.95 mm for the selected TBC using ANN method. Then the effects of coating thickness on frictional performance were revealed by generating transient structural FE models and utilizing stribeck diagram. The uncoated and 0.95 mm NiCrAlY–Gd2Zr2O7 coated models were adjusted as transient and the related crank angle – dependent in-cylinder combustion pressure data was implemented. The friction force was reduced by at least 15% in NiCrAlY–Gd2Zr2O7 coated model.

Aggregate Characteristics Governing Performance of Seal Coat Highway Overlays

1996 ◽  
Vol 1547 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Mohamed-Asem U. Abdul-Malak ◽  
David W. Fowler ◽  
Cesar A. Constantino
Keyword(s):  
Statistical Models ◽  
Environmental Variables ◽  
Construction Projects ◽  
Performance Data ◽  
Engineering Properties ◽  
Proper Selection ◽  
Performance Variability ◽  
Frictional Performance ◽  
Materials Used ◽  
Selection Of

A study was undertaken to identify the engineering properties of aggregates that explain the variability in the frictional performance of seal coat highway overlays. The frictional performance data of 72 test sections and section replicates collected over a period of 8 years were used in the formulation of statistical models that incorporate the significant variables. The effects of traffic, construction, and environmental variables were also considered. Formulated models were of two types: general and individual. The former type attempts to describe frictional performance using the observations collected on all aggregate materials used. The latter describes the performance of individual aggregate groups. Laboratory properties found to be significant included the polish value, impact and abrasion, and soundness properties. The coating of aggregate particles, gradation, and construction placing rates of aggregate and asphalt were also shown to be significant in explaining performance variability. The influence of traffic and region was found to be interactive with the type and properties of aggregates. The formulated models can be used as a tool for predicting the frictional performance of seal coat aggregates, thus providing a better means for the proper selection of aggregates and for the planning of future seal coat construction projects.

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