Miloš Stanković, Aleksandar Marinković, Aleksandar Grbović, Žarko Mišković, Božidar Rosić and Radivoje Mitrović
This paper aims to present the methodology to determine Archard’s wear coefficient. By applying this coefficient into the numerical simulation of wear, it is possible to predict…
Abstract
Purpose
This paper aims to present the methodology to determine Archard’s wear coefficient. By applying this coefficient into the numerical simulation of wear, it is possible to predict wear without long lasting and usually expensive experiments.
Design/methodology/approach
To determine necessary particles of Archard’s equation and calculate wear coefficient K, an experimental investigation is proposed. Afterwards, the wear simulation is executed in FEM software ANSYS 18.1. Analytical method is offered to determine worn volume for cylinder-in-cylinder contact, based on “inclination” of inner cylinder.
Findings
Comparing the value of Archard’s coefficient obtained by this experimental investigation with the values from the literature for the similar materials, high correlation is noted. Furthermore, numerically calculated contact pressure is confirmed with analytical method. Trend of pressure decrease due to wearing process, as well as due to increase of contact surface is observed.
Practical implications
Since the prediction of the wear is closely related to the life cycle assessment of bearings, and the machines in general, it has significant practical importance for designers.
Originality/value
Determination of Archard’s coefficient is usually performed by conventional pin-on-disk tribometers. This methodology offers a different approach for the determination of Archard’s wear coefficient for cylinder-in-cylinder contact, which is convenient for shaft-sliding bearing contact.
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Aleksandar Marinković, Božidar Rosić and Georgios Petropoulos
This paper aims to develop a simulating model of a journal porous metal bearing under elastohydrodynamic conditions and combined (radial, friction and thermal) load distribution…
Abstract
Purpose
This paper aims to develop a simulating model of a journal porous metal bearing under elastohydrodynamic conditions and combined (radial, friction and thermal) load distribution and to carry out structural optimization.
Design/methodology/approach
The structure analysis is carried out for each kind of load separately and for the combined load distribution of the bearing, where a dynamically loaded porous metal bearing is simulated. This simulating model is developed by finite elements method using the structure analysis module of the CATIA V5 software. Further, a parameter optimization of a porous metal bearing is presented considering the elastic deformations of the bearing shell.
Findings
It is revealed that the bearing, even at points with maximum displacements, could not reach the mounting clearance value during its operational life. Relatively small bearing dimensions produce very high values of eigenfrequency response (over 150 kHz) and common dynamic loads met in all sorts of sliding bearing are not dangerous for bearing damage compared with static loads. In the stage of structural optimization based on the correlation between stress and geometric bearing parameters like wall thickness and outer diameter, the influence of finite element dimension on calculated results can be also analyzed and a proper choice of the latter is achieved.
Research limitations/implications
The present porous bearing optimization model with the aid of CATIA V5 module for optimum design uses only single objective optimization. For a complete optimum design a multi‐objective optimization has to be carried out.
Practical implications
The analysis under dynamic load conditions proved that relatively small dimensions of bearing commonly used in micro technique and precision mechanics result in extended safe and reliable operation.
Originality/value
This paper provides a methodology for bearing stress and deformation analysis in the elastic range and on the basis of this analysis it is possible to develop an optimization model for porous bearings offering help to designers for the selection of optimal bearing dimensions considering the bearing load caused by dynamic radial force, friction and temperature variation.
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Zoran Kalinić, Veljko Marinković, Aleksandar Djordjevic and Francisco Liebana-Cabanillas
The purpose of this paper, which is based on the UTAUT2 model, is to develop and evaluate a predictive model of customer satisfaction related to mobile commerce (m-commerce) and…
Abstract
Purpose
The purpose of this paper, which is based on the UTAUT2 model, is to develop and evaluate a predictive model of customer satisfaction related to mobile commerce (m-commerce) and the willingness to recommend this service to others.
Design/methodology/approach
The study was conducted based on a sample of 402 respondents. Confirmative factor analysis was used to evaluate the validity of the model, while structural equation modeling (SEM) was used to test the hypotheses. Finally, artificial neural networks were used to rank the influence of the significant predictors obtained by SEM.
Findings
Trust was found to be the most significant driver of customer satisfaction, followed by performance expectancy and perceived value. In addition, affective commitment and satisfaction were identified as the strongest predictors of word of mouth (WOM).
Originality/value
The originality/value of the paper lies in the establishment of the connection between the independent variables of the UTAUT 2 model – trust, satisfaction, affective and continence commitment and WOM. Additionally, it is one of a small number of studies investigating customer commitments and their influence on WOM in m-commerce.
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Darko Dimitrovski, Veljko Marinković, Aleksandar Djordjevic and Erose Sthapit
This study aims to develop and test a model of the wellness spa hotel experience. The model proposes that experiencescape dimensions (sensory, functional, social, natural and…
Abstract
Purpose
This study aims to develop and test a model of the wellness spa hotel experience. The model proposes that experiencescape dimensions (sensory, functional, social, natural and hospitality culture) are important antecedents of guest satisfaction with a wellness spa hotel experience. The study also tests the relationship between satisfaction, wellness-induced well-being, experience co-creation and word-of-mouth (WOM).
Design/methodology/approach
Data was collected in the post-pandemic period, during September–November 2022 from 567 domestic guests who had stayed in a wellness spa hotel in Serbia.
Findings
Besides the social experience scape dimension, all other dimensions of experiencescape (sensory, functional, natural and hospitality culture) were found to be positive drivers of guest satisfaction with a wellness spa hotel experience. The relationship between satisfaction, wellness-induced well-being, experience co-creation and WOM was also supported.
Originality/value
This study emphasises the role of experiencescape in concurrence with the antecedents in cultivating guest satisfaction with a wellness spa hotel experience, which further influences wellness-induced well-being, experience co-creation and WOM.
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Aleksandar Vencl, Ilija Bobic and Blaza Stojanovic
Aluminium alloys are frequently applied in automotive and other industries, since they provide mass reduction. Besides positive effects, aluminium alloys have their shortcomings…
Abstract
Purpose
Aluminium alloys are frequently applied in automotive and other industries, since they provide mass reduction. Besides positive effects, aluminium alloys have their shortcomings reflected, first of all, in inappropriate tribological properties of these materials. The aim of this research was to enable the production of cheap aluminium alloy matrix composite with favourable combination of structural, mechanical and tribological properties, focusing on the tribological behaviour.
Design/methodology/approach
The A356 Al-Si alloy was used as a matrix for producing metal matrix composites in compocasting process. Three different materials, in form of particles, were added to the matrix (Al2O3, SiC and graphite). Hardness and tribological properties (wear, friction and wear mechanism) of heat-treated (T6) samples were examined and compared. Tribological tests were carried out on ball-on-block tribometer under dry sliding conditions. Sliding was linear (reciprocating). Counter body was alumina ball. Average velocity was 0.038 m/s (max. 0.06 m/s), sliding distance was 500 m and normal load was 1 N.
Findings
The effect of two different ceramic particles and graphite particles on tribological properties of obtained composites was evaluated. Wear resistance of composites reinforced with SiC particles was higher and coefficient of friction was lower compared to the composite reinforced with Al2O3 particles. A dual hybrid composite (with SiC and graphite particles) showed the lowest value of wear rate and friction coefficient. Dominant wear mechanism for all tested material was adhesion.
Research limitations/implications
It seems useful to continue the work on developing hybrid composites containing soft graphite particles with A356 Al-Si alloy as matrix. The major task should be to improve particles distribution (especially with higher graphite content) and to explore tribological behaviour in diverse working conditions.
Originality/value
Particulate composites with A356 aluminium alloy as a matrix produced in compocasting process using ceramic particles (Al2O3, SiC) were investigated in many researches, but there are only few detailed analyses of dual composites (with the addition of ceramic and graphite particles). In some previous studies, it was shown that compocasting process, as relatively cheap technology, can obtain good structural and mechanical characteristics of composites. In this study, it was shown that even a low graphite content, under specified conditions, can improve tribological properties.