F. Al-Bender, F. Colombo, D. Reynaerts, R. Villavicencio, T. Waumans
This paper concerns the dynamic characterization of rubber O-rings used to introduce damping in high speed gas bearing systems. O-shaped rubber rings composed of high temperature rubber compounds are characterized in terms of stiffness and damping coefficients in the frequency range 100–800 Hz. Simple formulas with frequency independent coefficients were identified to express the viscoelastic properties of the O-rings. The formulas proposed approximate the stiffness and damping coefficients of O-rings of general size.
{"title":"Dynamic Characterization of Rubber O-Rings: Squeeze and Size Effects","authors":"F. Al-Bender, F. Colombo, D. Reynaerts, R. Villavicencio, T. Waumans","doi":"10.1155/2017/2509879","DOIUrl":"https://doi.org/10.1155/2017/2509879","url":null,"abstract":"This paper concerns the dynamic characterization of rubber O-rings used to introduce damping in high speed gas bearing systems. O-shaped rubber rings composed of high temperature rubber compounds are characterized in terms of stiffness and damping coefficients in the frequency range 100–800 Hz. Simple formulas with frequency independent coefficients were identified to express the viscoelastic properties of the O-rings. The formulas proposed approximate the stiffness and damping coefficients of O-rings of general size.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2017-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/2509879","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49471361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The concept of two-disc model testing has proven to deliver valuable information for the applicability of new technologies, such as surface structuring, coatings, alternative fluids, or advanced materials, in actual machine elements. In this article an advanced two-disc machine with sophisticated control technology for dry and lubricated setup is presented. (i) All involved components are controlled via a powerful PLC unit leading to the possibility of realising extremely accurate SRRs down to . (ii) High-speed data acquisition allows local insight into tribological phenomena by providing 72 data points along one shaft rotation. (iii) Several lubrication scenarios such as fluid, mixed, and starved lubrication, as well as dry contacts, can be considered. (iv) Raw-data of all sensors, including normal force, friction force, vibration speed, stiffness (wear), infrared temperature, contact potential, and motor speed, is presented. Some example results of dry polymer-steel tribosystems and lubricated experiments are shown to elucidate the capabilities of the novel test rig.
{"title":"A Novel Two-Disc Machine for High Precision Friction Assessment","authors":"Jakob Moder, F. Grün, M. Stoschka, I. Gódor","doi":"10.1155/2017/8901907","DOIUrl":"https://doi.org/10.1155/2017/8901907","url":null,"abstract":"The concept of two-disc model testing has proven to deliver valuable information for the applicability of new technologies, such as surface structuring, coatings, alternative fluids, or advanced materials, in actual machine elements. In this article an advanced two-disc machine with sophisticated control technology for dry and lubricated setup is presented. (i) All involved components are controlled via a powerful PLC unit leading to the possibility of realising extremely accurate SRRs down to . (ii) High-speed data acquisition allows local insight into tribological phenomena by providing 72 data points along one shaft rotation. (iii) Several lubrication scenarios such as fluid, mixed, and starved lubrication, as well as dry contacts, can be considered. (iv) Raw-data of all sensors, including normal force, friction force, vibration speed, stiffness (wear), infrared temperature, contact potential, and motor speed, is presented. Some example results of dry polymer-steel tribosystems and lubricated experiments are shown to elucidate the capabilities of the novel test rig.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2017-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/8901907","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48281226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present study analyzes the effect of pressure dam depth and relief track depth on the performance of three-lobe pressure dam bearing. Different values of dam depth and relief track depth are taken in nondimensional form in order to analyze their effect. Results are plotted for different parameters against eccentricity ratios and it is shown that the effect of pressure dam depth and relief track depth has great significance on stability and other performance parameters. Study of stability and performance characteristics is undertaken simultaneously.
{"title":"Effect of Dam Depth and Relief Track Depth on Steady-State and Dynamic Performance Parameters of 3-Lobe Pressure Dam Bearing","authors":"Ashutosh Kumar, S. Kakoty","doi":"10.1155/2017/1380367","DOIUrl":"https://doi.org/10.1155/2017/1380367","url":null,"abstract":"The present study analyzes the effect of pressure dam depth and relief track depth on the performance of three-lobe pressure dam bearing. Different values of dam depth and relief track depth are taken in nondimensional form in order to analyze their effect. Results are plotted for different parameters against eccentricity ratios and it is shown that the effect of pressure dam depth and relief track depth has great significance on stability and other performance parameters. Study of stability and performance characteristics is undertaken simultaneously.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2017-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/1380367","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48750788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Sukumaran, R. Keresztes, G. Kalácska, H. Al-Maliki, P. Neis, P. Baets
Polyamide (PA6/6) is often used as a tribological pair in abrasion prevalent applications such as hinges and sliders. PA6/6 is frequently processed by injection moulding and extrusion process. It is known that these processes influence the polymers mechanical behaviour, but their influence on the polymers wear response has not been studied. Hence the present research attempts to study the influence of different manufacturing processes on tribological behaviour for PA6/6. Wear tests were performed on a pin abrading tester (DIN 50322). Abrasion resistance of both extruded and injection moulded PA6/6 were tested at different loads (20 and 35 N). Single-pass (nonoverlapping mode) and multipass testing (overlapping mode) were used to understand the influence of clogging of wear debris. It is evidenced that with increasing load the specific wear rate decreases; moreover, fine abrasives tend to reduce the wear rate. In multipass testing a transfer layer clogged on the counterface that acted as a protective agent and lowers wear rate. Poor mechanical strength of injection moulded polymers is apparently compensated by microstructural response for having a similar wear behaviour between extruded and injection moulded PA 6/6. Hence a proper balance between microstructural and mechanical characteristics is an absolute must in PA 6/6 for better wear performance.
{"title":"Extruded and Injection Moulded Virgin PA 6/6 as Abrasion Resistant Material","authors":"J. Sukumaran, R. Keresztes, G. Kalácska, H. Al-Maliki, P. Neis, P. Baets","doi":"10.1155/2017/1035017","DOIUrl":"https://doi.org/10.1155/2017/1035017","url":null,"abstract":"Polyamide (PA6/6) is often used as a tribological pair in abrasion prevalent applications such as hinges and sliders. PA6/6 is frequently processed by injection moulding and extrusion process. It is known that these processes influence the polymers mechanical behaviour, but their influence on the polymers wear response has not been studied. Hence the present research attempts to study the influence of different manufacturing processes on tribological behaviour for PA6/6. Wear tests were performed on a pin abrading tester (DIN 50322). Abrasion resistance of both extruded and injection moulded PA6/6 were tested at different loads (20 and 35 N). Single-pass (nonoverlapping mode) and multipass testing (overlapping mode) were used to understand the influence of clogging of wear debris. It is evidenced that with increasing load the specific wear rate decreases; moreover, fine abrasives tend to reduce the wear rate. In multipass testing a transfer layer clogged on the counterface that acted as a protective agent and lowers wear rate. Poor mechanical strength of injection moulded polymers is apparently compensated by microstructural response for having a similar wear behaviour between extruded and injection moulded PA 6/6. Hence a proper balance between microstructural and mechanical characteristics is an absolute must in PA 6/6 for better wear performance.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/1035017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64647595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The physicochemical and tribological studies of mineral and synthetic commercial engine oils have been carried out to investigate their performance variability and to propose generalized relationship among different physicochemical and performance parameters. Physicochemical parameters have been determined using standard test procedures proposed in ASTM and Indian Standards (BIS). The rheological parameters of these lubricants have been investigated to identify the flow behavior. The tribological performance in terms of their antifriction and antiwear properties has been studied using four-ball tribotester. Correlation and regression analysis has been performed to ascertain relationship among physicochemical and tribological parameters and the causes of performance variability are highlighted. An empirical relation to calculate coefficient of friction as a function of physicochemical properties has been established using regression analysis. The developed relation has fair degree of reliability, as percentage of deviation is less than 20%.
{"title":"Correlation Study of Physicochemical, Rheological, and Tribological Parameters of Engine Oils","authors":"P. Thapliyal, G. D. Thakre","doi":"10.1155/2017/1257607","DOIUrl":"https://doi.org/10.1155/2017/1257607","url":null,"abstract":"The physicochemical and tribological studies of mineral and synthetic commercial engine oils have been carried out to investigate their performance variability and to propose generalized relationship among different physicochemical and performance parameters. Physicochemical parameters have been determined using standard test procedures proposed in ASTM and Indian Standards (BIS). The rheological parameters of these lubricants have been investigated to identify the flow behavior. The tribological performance in terms of their antifriction and antiwear properties has been studied using four-ball tribotester. Correlation and regression analysis has been performed to ascertain relationship among physicochemical and tribological parameters and the causes of performance variability are highlighted. An empirical relation to calculate coefficient of friction as a function of physicochemical properties has been established using regression analysis. The developed relation has fair degree of reliability, as percentage of deviation is less than 20%.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/1257607","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64648992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Staffan Johansson, P. Nilsson, R. Ohlsson, B. Rosén
An important parameter in the reduction of fuel consumption of heavy-duty diesel engines is the Power Cylinder Unit (PCU); the PCU is the single largest contributor to engine frictional losses. Much attention, from both academia and industry, has been paid to reducing the frictional losses of the PCU in the boundary and mixed lubrication regime. However, previous studies have shown that a large portion of frictional losses in the PCU occur in the hydrodynamic lubrication regime. A novel texturing design with large types of surface features was experimentally analyzed using a tribometer setup. The experimental result shows a significant reduction of friction loss for the textured surfaces. Additionally, the textured surface did not exhibit wear. On the contrary, it was shown that the textured surfaces exhibited a smaller amount of abrasive scratches on the plateaus (compared to the reference plateau honed surface) due to entrapment of wear particles within the textures. The decrease in hydrodynamic friction for the textured surfaces relates to the relative increase of oil film thickness within the textures. A tentative example is given which describes a method of decreasing hydrodynamic frictional losses in the full-scale application.
{"title":"A Novel Approach to Reduction of Frictional Losses in a Heavy-Duty Diesel Engine by Reducing the Hydrodynamic Frictional Losses","authors":"Staffan Johansson, P. Nilsson, R. Ohlsson, B. Rosén","doi":"10.1155/2017/9240703","DOIUrl":"https://doi.org/10.1155/2017/9240703","url":null,"abstract":"An important parameter in the reduction of fuel consumption of heavy-duty diesel engines is the Power Cylinder Unit (PCU); the PCU is the single largest contributor to engine frictional losses. Much attention, from both academia and industry, has been paid to reducing the frictional losses of the PCU in the boundary and mixed lubrication regime. However, previous studies have shown that a large portion of frictional losses in the PCU occur in the hydrodynamic lubrication regime. A novel texturing design with large types of surface features was experimentally analyzed using a tribometer setup. The experimental result shows a significant reduction of friction loss for the textured surfaces. Additionally, the textured surface did not exhibit wear. On the contrary, it was shown that the textured surfaces exhibited a smaller amount of abrasive scratches on the plateaus (compared to the reference plateau honed surface) due to entrapment of wear particles within the textures. The decrease in hydrodynamic friction for the textured surfaces relates to the relative increase of oil film thickness within the textures. A tentative example is given which describes a method of decreasing hydrodynamic frictional losses in the full-scale application.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/9240703","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64719100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Airborne particulate emissions originating from the wear of pads and rotors of disc brakes contribute up to 50% of the total road emissions in Europe. The wear process that takes place on a mesoscopic length scale in the contact interfaces between the pads and rotors can be explained by the creation and destruction of contact plateaus. Due to this complex contact situation, it is hard to predict how changes in the wear and material parameters of the pad friction material will affect the friction and wear emissions. This paper reports on an investigation of the effect of different parameters of the pad friction material on the coefficient of friction and wear emissions. A full factorial design is developed using a simplified version of a previously developed cellular automaton approach to investigate the effect of four factors on the coefficient of friction and wear emission. The simulated result indicates that a stable third body, a high specific wear, and a relatively high amount of metal fibres yield a high and stable mean coefficient of friction, while a stable third body, a low specific wear, a stable resin, and a relatively high amount of metal fibres give low wear emissions.
{"title":"A Factorial Design to Numerically Study the Effects of Brake Pad Properties on Friction and Wear Emissions","authors":"J. Wahlström","doi":"10.1155/2016/8181260","DOIUrl":"https://doi.org/10.1155/2016/8181260","url":null,"abstract":"Airborne particulate emissions originating from the wear of pads and rotors of disc brakes contribute up to 50% of the total road emissions in Europe. The wear process that takes place on a mesoscopic length scale in the contact interfaces between the pads and rotors can be explained by the creation and destruction of contact plateaus. Due to this complex contact situation, it is hard to predict how changes in the wear and material parameters of the pad friction material will affect the friction and wear emissions. This paper reports on an investigation of the effect of different parameters of the pad friction material on the coefficient of friction and wear emissions. A full factorial design is developed using a simplified version of a previously developed cellular automaton approach to investigate the effect of four factors on the coefficient of friction and wear emission. The simulated result indicates that a stable third body, a high specific wear, and a relatively high amount of metal fibres yield a high and stable mean coefficient of friction, while a stable third body, a low specific wear, a stable resin, and a relatively high amount of metal fibres give low wear emissions.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2016/8181260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64553390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The friction of ice on other materials controls loading on offshore structures and vessels in the Arctic. However, ice friction is complicated, because ice in nature exists near to its melting point. Frictional heating can cause local softening, and perhaps melting and lubrication, thus affecting the friction and creating a feedback loop. Ice friction is therefore likely to depend on sliding speed and sliding history, as well as bulk temperature. The roughness of the sliding materials may also affect the friction. Here we present results of a series of laboratory experiments, sliding saline ice on aluminium, and controlling for roughness and temperature. We find that the friction of saline ice on aluminium, μice-al = 0.1 typically, but that this value varies with sliding conditions. We propose physical models which explain the variations in sliding friction.
{"title":"The Friction of Saline Ice on Aluminium","authors":"Christopher Wallen-Russell, B. Lishman","doi":"10.1155/2016/1483951","DOIUrl":"https://doi.org/10.1155/2016/1483951","url":null,"abstract":"The friction of ice on other materials controls loading on offshore structures and vessels in the Arctic. However, ice friction is complicated, because ice in nature exists near to its melting point. Frictional heating can cause local softening, and perhaps melting and lubrication, thus affecting the friction and creating a feedback loop. Ice friction is therefore likely to depend on sliding speed and sliding history, as well as bulk temperature. The roughness of the sliding materials may also affect the friction. Here we present results of a series of laboratory experiments, sliding saline ice on aluminium, and controlling for roughness and temperature. We find that the friction of saline ice on aluminium, μice-al = 0.1 typically, but that this value varies with sliding conditions. We propose physical models which explain the variations in sliding friction.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2016/1483951","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64225912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hong Liu, Haijun Wei, Lidui Wei, Jing-ming Li, Zhiyuan Yang
This study aims to use a JSEG algorithm to segment the wear particle’s image. Wear particles provide detailed information about the wear processes taking place between mechanical components. Autosegmentation of their images is key to intelligent classification system. This study examined whether this algorithm can be used in particles’ image segmentation. Different scales have been tested. Compared with traditional thresholding along with edge detector, the JSEG algorithm showed promising result. It offers a relatively higher accuracy and can be used on color image instead of gray image with little computing complexity. A conclusion can be drawn that the JSEG method is suited for imaged wear particle segmentation and can be put into practical use in wear particle’s identification system.
{"title":"The Segmentation of Wear Particles Images Using -Segmentation Algorithm","authors":"Hong Liu, Haijun Wei, Lidui Wei, Jing-ming Li, Zhiyuan Yang","doi":"10.1155/2016/4931502","DOIUrl":"https://doi.org/10.1155/2016/4931502","url":null,"abstract":"This study aims to use a JSEG algorithm to segment the wear particle’s image. Wear particles provide detailed information about the wear processes taking place between mechanical components. Autosegmentation of their images is key to intelligent classification system. This study examined whether this algorithm can be used in particles’ image segmentation. Different scales have been tested. Compared with traditional thresholding along with edge detector, the JSEG algorithm showed promising result. It offers a relatively higher accuracy and can be used on color image instead of gray image with little computing complexity. A conclusion can be drawn that the JSEG method is suited for imaged wear particle segmentation and can be put into practical use in wear particle’s identification system.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2016/4931502","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64404091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present study involves field testing of a tire-loading-based theory of pavement traction in place of the traditional coefficient of friction. An associated hypothesis concerns the indicated existence of a fourth rubber force, surface deformation hysteresis, which is theorized to be independent of tire loading during tire sliding.
{"title":"A Rational Theory of Tire-Pavement Friction","authors":"Robert Smith, W. Uddin","doi":"10.1155/2016/4858317","DOIUrl":"https://doi.org/10.1155/2016/4858317","url":null,"abstract":"The present study involves field testing of a tire-loading-based theory of pavement traction in place of the traditional coefficient of friction. An associated hypothesis concerns the indicated existence of a fourth rubber force, surface deformation hysteresis, which is theorized to be independent of tire loading during tire sliding.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2016-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2016/4858317","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64401580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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