scholarly journals Analysis of High-Friction Surface Texture with Respect to Friction and Wear

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 758
Author(s):  
Cibi Pranav ◽  
Minh-Tan Do ◽  
Yi-Chang Tsai

High Friction Surfaces (HFS) are applied to increase friction capacity on critical roadway sections, such as horizontal curves. HFS friction deterioration on these sections is a safety concern. This study deals with characterization of the aggregate loss, one of the main failure mechanisms of HFS, using texture parameters to study its relationship with friction. Tests are conducted on selected HFS spots with different aggregate loss severity levels at the National Center for Asphalt Technology (NCAT) Test Track. Friction tests are performed using a Dynamic Friction Tester (DFT). The surface texture is measured by means of a high-resolution 3D pavement scanning system (0.025 mm vertical resolution). Texture data are processed and analyzed by means of the MountainsMap software. The correlations between the DFT friction coefficient and the texture parameters confirm the impact of change in aggregates’ characteristics (including height, shape, and material volume) on friction. A novel approach to detect the HFS friction coefficient transition based on aggregate loss, inspired by previous works on the tribology of coatings, is proposed. Using the proposed approach, preliminary outcomes show it is possible to observe the rapid friction coefficient transition, similar to observations at NCAT. Perspectives for future research are presented and discussed.

2018 ◽  
Vol 11 (2) ◽  
pp. 222 ◽  
Author(s):  
José Luis Ruano Pérez ◽  
Raúl Rodríguez-Rodríguez ◽  
Juan-José Alfaro Saiz ◽  
María-José Verdecho

Purpose: The main objective of this research is to design a decision-making network, based on the Analytic Network Process (ANP) technique (Saaty, 1996), which will include the main elements to take into account when stating the effect that the application of LP techniques has got on the performance of an organisation, measured this through a Performance Measurement System (PMS).Design/methodology/approach: The authors have carried out a scientific literature search to state what the main LP techniques are –and how to group them into different clusters- and have then applied the ANP, its first phase, in order to design the decisional network.Findings: There is a gap in the literature when trying to identify and quantify to what extent the implementation of LP techniques affects to organisational performance. The ANP is an appropriate technique to do so due to the need of gathering and quantifying experts’ opinions.Originality/value: The designed ANP-based network to measure the impact of LP over organisational performance is a novel approach. This paper justifies its usage and paves the way to implement the rest of the ANP phases in future research work. 


Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 639 ◽  
Author(s):  
Tomasz Kozior ◽  
Jerzy Bochnia

Laser technologies for fast prototyping using metal powder-based materials allow for faster production of prototype constructions actually used in the tooling industry. This paper presents the results of measurements on the surface texture of flat samples and the surface texture of a prototype of a reduced-mass lathe chuck, made with the additive technology—powder bed fusion. The paper presents an analysis of the impact of samples’ orientation on the building platform on the surface geometrical texture parameters (two-dimensional roughness profile parameters (Ra, Rz, Rv, and so on) and spatial parameters (Sa, Sz, and so on). The research results showed that the printing orientation has a very large impact on the quality of the surface texture and that it is possible to set digital models on the building platform (parallel—0° to the building platform plane), allowing for manufacturing models with low roughness parameters. This investigation is especially important for the design and 3D printing of microelectromechanical systems (MEMS) models, where surface texture quality and printable resolution are still a large problem.


Author(s):  
Zhanqi Tang ◽  
Xiaojun Liu ◽  
Kun Liu

Surface texturing is a widely used method to improve the tribological performance of the mechanical systems. To introduce the surface texture into the mechanical components, this study experimentally examined the frictional behaviors of grease lubricated spherical plain bearings under mixed lubrication conditions on an electro-hydraulic servo tribological test rig. The effects of the surface texture parameters and roughness parameters on the frictional properties of bearings were investigated. The results showed that higher dimple depths and lower dimple densities would result in a distinct improvement on the friction coefficients. A maximum reduction of 55% was gained for the textured sample under running conditions compared with the untextured one. In addition, the surface roughness parameters also influence the frictional behaviors. In the high load conditions, the friction coefficient decreases while the Ssk value gets more negative, even though the Sa value is much higher. On the other hand, in the low load conditions, when the value of Ssk varies between −5 and −1, the influence of the value of Sa on the friction coefficient becomes obvious, a higher Sa value results in a higher friction coefficient.


Author(s):  
Danielle Lottridge ◽  
Mark Chignell

The impact of notifications on driving performance is a critical safety concern (Lee & Strayer, 2004). This study examined how interruptions (including phone calls) impair simulated driving performance, and how individual differences mediate the effect of those interruptions. Consistent with our hypothesis, field dependent participants answered phone calls more quickly and with less consideration of the difficulty of the current driving situation than more field independent participants. Further, a post-hoc analysis showed that, on average, field dependents with small operating spans crashed twice as often as the other drivers. Thus the detrimental effect of a field dependent style on managing interruptions while driving is likely worsened for people with low working memory capacity. It is suggested that future research should investigate the safety implications of individual differences in interruption handling ability. Such research is needed to support ongoing efforts to develop guidelines and legislation concerning the use of distracting information technologies (such as cell phones) in automobiles.


2016 ◽  
Vol 68 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Rufei Yu ◽  
Pei Li ◽  
Wei Chen

Purpose – This paper aims to study the impact of surface texture on grease-lubricated journal bearing, load-carrying capacity, friction and friction coefficient. Design/methodology/approach – The paper opted for a basic application research using the commercial CFD software FLUENT 14.0. Findings – The load-carrying capacity can be enhanced if the surface texture is introduced from a suitable position. The textural shape has a more significant effect on the friction and load-carrying capacity than the friction coefficient. The rheological parameters of grease affect the load-carrying capacity in the same way, i.e. the load increases with the increase in the rheological parameters. With the decrease in the value of cavitation pressure, the cavitation area reduces but the dynamic pressure area gets enlarged. Research limitations/implications – Because of the chosen research method, the research results may lack the analysis of experiments. Practical implications – The research results can be applied to the domain in the high-speed spindle and lubricated multibody system. Originality/value – The investigation on the performances of grease-lubricated journal bearing with surface texture would be significant.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wen’an Wang ◽  
Zhiqi Liu ◽  
Dongliang Chen ◽  
Zhiming Xie ◽  
Jianli Song

The surface texture, a major way to decrease friction and wear of the cylinder-piston ring friction pair, was conducted on cylinder-piston ring friction pair specimen using the orthogonal experimental design method to investigate the effect of different texture parameters (size, depth, shape, and surface density) of the friction and wear characteristics. Through simulation analysis, the texture parameters that affect the friction and wear characteristics are obtained. Using the evaluation method of friction coefficient and mass wear rate, the influence sequence and optimal values of texture parameters that affect friction and wear characteristics are obtained through range analysis. The results show that, after surface texture treatment under mixed lubrication conditions, the friction characteristics of the friction pair have changed and the friction coefficient and friction and wear rate have been significantly reduced. The results show that the triangular texture has a good antifriction effect, the texture depth is deepened, and the surface density and the size increases have a positive effect on the improvement of friction and wear. An ultra-depth microscope was used to observe the wear morphology of the friction and wear tests. The results show that the weakening of the third body wear by the texturing treatment and the maintenance of oil lubrication are the main reasons for reducing friction and wear.


2020 ◽  
Vol 29 (4) ◽  
pp. 2097-2108
Author(s):  
Robyn L. Croft ◽  
Courtney T. Byrd

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.


Author(s):  
Endy Gunanto ◽  
Yenni Kurnia Gusti

In this article we present a conceptual of the effect of cross culture on consumer behavior incorporating the impact of globalization. This conceptual idea shows that culture inûuences various domains of consumer behavior directly as well as through international organization to implement marketing strategy. The conceptual identify several factors such as norm and value in the community, several variables and also depicts the impact of other environmental factors and marketing strategy elements on consumer behavior. We also identify categories of consumer culture orientation resulting from globalization. Highlights of each of the several other articles included in this special issue in Asia region. We conclude with the contributions of the articles in terms of the consumer cultural orientations and identify directions for future research.


2020 ◽  
Vol 91 (8) ◽  
pp. 651-661
Author(s):  
Joshua T. Davis ◽  
Hilary A. Uyhelji

INTRODUCTION: Although the impact of microorganisms on their hosts has been investigated for decades, recent technological advances have permitted high-throughput studies of the collective microbial genomes colonizing a host or habitat, also known as the microbiome. This literature review presents an overview of microbiome research, with an emphasis on topics that have the potential for future applications to aviation safety. In humans, research is beginning to suggest relationships of the microbiome with physical disorders, including type 1 and type 2 diabetes mellitus, cardiovascular disease, and respiratory disease. The microbiome also has been associated with psychological health, including depression, anxiety, and the social complications that arise in autism spectrum disorders. Pharmaceuticals can alter microbiome diversity, and may lead to unintended consequences both short and long-term. As research strengthens understanding of the connections between the microbiota and human health, several potential applications for aerospace medicine and aviation safety emerge. For example, information derived from tests of the microbiota has potential future relevance for medical certification of pilots, accident investigation, and evaluation of fitness for duty in aerospace operations. Moreover, air travel may impact the microbiome of passengers and crew, including potential impacts on the spread of disease nationally and internationally. Construction, maintenance, and cleaning regimens that consider the potential for microbial colonization in airports and cabin environments may promote the health of travelers. Altogether, the mounting knowledge of microbiome effects on health presents several opportunities for future research into how and whether microbiome-based insights could be used to improve aviation safety.Davis JT, Uyhelji HA. Aviation and the microbiome. Aerosp Med Hum Perform. 2020; 91(8):651–661.


Author(s):  
Dzhyhil Yu. ◽  

Residential architecture has one of the most conservative styles based on its specifics. However, today this type of architecture seeks to actively respond to changes in the modern world. These changes are caused by multiple factors, among them are: technological and information progress; lack of resources and environmental pollution; military conflicts and population migration etc. The purpose of this article is to summarize the experience of the Department of Architectural Environment of Lviv Polytechnic National University over housing issues and outline the methodological principles of innovation in designing both individual houses and the architectural environment of residential formations. While writing this article, we analyzed the 15-year experience of Architectural Environment's Department diploma projects. The unique feature of these projects is the priority on the design of the environment. The evolution of diploma project topics is revealed on multiple distinctive examples such as the reconstruction of old buildings in Lviv and the construction of prefabricated homes and container-type housing. Futuristic settlements are represented in projects such as “The Ocean Settlements” and “Prykarpatsk - the City of Future”. Research projects were developed to study current trends in housing design and the impact of innovative technologies on planning decisions. These projects discoursed the protection of housing from traffic noise and issues related to environmental preservation. Innovative architectural ideas of future housing, developed by students in these projects, are based on a combination of aesthetic, technical, and social components of architecture. The conclusion indicates that when educating future architects, it is important to teach them the basics of the craft, as well as the ability to defend their innovative ideas. The emphasis is placed on the importance of educating the architect's personal responsibility for their own design solutions. It is stated that professional motivation and the ability to constantly renew previously acquired knowledge and skills will be among the main tasks in training future architects.


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