Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780015
S. Kharin
The mathematical model describing welding at contact closure is elaborated. All consecutive stages of contact closure are considered including the first touch of micro-asperities with micro-arcing, initial contact heating, softening, melting and boiling of the contact surface. Two possible phenomena are discussed, welding and bouncing. It is shown that everything depends on the relationship between dynamical characteristics of heating and contact motion such as spreading of melting and softening zones on the contact surface, action of elastic-plastic, electrodynamic and contact spring forces, metallic vapors pressure, parameters of the contact material, circuit parameters and some other factors. The mathematical model is based on the axisymmetric Stefan problem which takes into account phase transformations of the contact material. Some new methods for the solution of this problem are presented. The results of calculation are compared with experimental data.
{"title":"The influence of phase transformations on welding at contact closure","authors":"S. Kharin","doi":"10.1109/HOLM.2016.7780015","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780015","url":null,"abstract":"The mathematical model describing welding at contact closure is elaborated. All consecutive stages of contact closure are considered including the first touch of micro-asperities with micro-arcing, initial contact heating, softening, melting and boiling of the contact surface. Two possible phenomena are discussed, welding and bouncing. It is shown that everything depends on the relationship between dynamical characteristics of heating and contact motion such as spreading of melting and softening zones on the contact surface, action of elastic-plastic, electrodynamic and contact spring forces, metallic vapors pressure, parameters of the contact material, circuit parameters and some other factors. The mathematical model is based on the axisymmetric Stefan problem which takes into account phase transformations of the contact material. Some new methods for the solution of this problem are presented. The results of calculation are compared with experimental data.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116195923","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780009
Hong Liu, J. McBride
A gold coated multi-walled carbon nanotube (Au/MWCNT) composite has been used as a surface material in electrical contacts to improve the lifetime of micro-switches. A modified nano-indentation setup, with a 2 mm-diameter gold coated stainless steel probe making contact with the Au/MWCNT composite, has been used to investigate the electrical behavior of the composite. The contact forces are ranged from 0.2 mN to 2 mN. A finite element (FE) contact model is developed, linked to the nano-indentation tests. The composite is modeled as a bi-layered structure, and surface roughness is included in the modeling. The contact area is calculated from the modeling. The effective resistivity for the surface is used to determine the contact resistance, using the Holm equation. The calculated force-resistances are based on a number of assumptions and show the same trend as the experimental results.
{"title":"A finite element based electrical resistance study for rough surfaces: Applied to a bi-layered Au/MWCNT composite for micro-switching applications","authors":"Hong Liu, J. McBride","doi":"10.1109/HOLM.2016.7780009","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780009","url":null,"abstract":"A gold coated multi-walled carbon nanotube (Au/MWCNT) composite has been used as a surface material in electrical contacts to improve the lifetime of micro-switches. A modified nano-indentation setup, with a 2 mm-diameter gold coated stainless steel probe making contact with the Au/MWCNT composite, has been used to investigate the electrical behavior of the composite. The contact forces are ranged from 0.2 mN to 2 mN. A finite element (FE) contact model is developed, linked to the nano-indentation tests. The composite is modeled as a bi-layered structure, and surface roughness is included in the modeling. The contact area is calculated from the modeling. The effective resistivity for the surface is used to determine the contact resistance, using the Holm equation. The calculated force-resistances are based on a number of assumptions and show the same trend as the experimental results.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124019999","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780034
K. Mori, H. Takada, Tetsuo Shimizu, S. Kawabata, Miyuki. Tanaka, T. Kubo
With the advent of nanotechnology research, new nano-materials and nano-structural devices have been invented and fabricated. Particularly low dimensional materials such as fullerene, carbon nanotube and graphene have been investigated intensively in order to realize new functional electronic devices on a smaller scale. Since graphene surface is inactive chemically and electrically conductive, graphene film on copper is thought to be a promising electrical contact material to prevent from oxidation in air and we have started to investigate the electrical contact property with nano-indentation manipulator in scanning electron microscope. Force-resistance characteristics with and without graphene on copper were measured. Compared with copper foil, graphene film showed very stable and conductive force-resistance characteristics even after oxidation process of 180°C for 16 hours in air condition. This indicates that graphene coating is very effective to refrain from surface oxidation on copper substrate.
{"title":"The investigation of graphene film as a new electrical contact material","authors":"K. Mori, H. Takada, Tetsuo Shimizu, S. Kawabata, Miyuki. Tanaka, T. Kubo","doi":"10.1109/HOLM.2016.7780034","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780034","url":null,"abstract":"With the advent of nanotechnology research, new nano-materials and nano-structural devices have been invented and fabricated. Particularly low dimensional materials such as fullerene, carbon nanotube and graphene have been investigated intensively in order to realize new functional electronic devices on a smaller scale. Since graphene surface is inactive chemically and electrically conductive, graphene film on copper is thought to be a promising electrical contact material to prevent from oxidation in air and we have started to investigate the electrical contact property with nano-indentation manipulator in scanning electron microscope. Force-resistance characteristics with and without graphene on copper were measured. Compared with copper foil, graphene film showed very stable and conductive force-resistance characteristics even after oxidation process of 180°C for 16 hours in air condition. This indicates that graphene coating is very effective to refrain from surface oxidation on copper substrate.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132195509","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780011
K. Meyyappan, Qifeng Wu, V. Vasudevan, M. Vujosevic
Electrical contacts provide means for a separable connection between two current carrying conductors. Sockets containing these contacts could be exposed to mechanical vibration due to shipping, which can result in micromotion between mating surfaces. Repeated micromotion/fretting could lead to wearout of the protective gold layer and expose the base metal that can oxidize. Traditional laboratory based fretting experiments may not reflect the field reliability risks. In this study, a predictive capability is developed to investigate contact fretting in a socket due to random vibration using a finite element approach. Considering the degrees of freedom involved in the analysis and the resolution needed, a multiscale modeling approach utilizing global models with substructures to track high risk areas and local models to monitor fretting wear on the highest risk contact is employed. This approach allowed the study of micromotion at the contact interface, capturing stick-slip phenomenon, which can influence fretting wear. Predictions are validated through extensive experimentation, which includes matching of fretting risk areas, matching dynamic responses, and matching of fretting wipe lengths and location through image processing techniques.
{"title":"Predicting vibration-induced fretting in land grid array sockets in simulated field scenarios","authors":"K. Meyyappan, Qifeng Wu, V. Vasudevan, M. Vujosevic","doi":"10.1109/HOLM.2016.7780011","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780011","url":null,"abstract":"Electrical contacts provide means for a separable connection between two current carrying conductors. Sockets containing these contacts could be exposed to mechanical vibration due to shipping, which can result in micromotion between mating surfaces. Repeated micromotion/fretting could lead to wearout of the protective gold layer and expose the base metal that can oxidize. Traditional laboratory based fretting experiments may not reflect the field reliability risks. In this study, a predictive capability is developed to investigate contact fretting in a socket due to random vibration using a finite element approach. Considering the degrees of freedom involved in the analysis and the resolution needed, a multiscale modeling approach utilizing global models with substructures to track high risk areas and local models to monitor fretting wear on the highest risk contact is employed. This approach allowed the study of micromotion at the contact interface, capturing stick-slip phenomenon, which can influence fretting wear. Predictions are validated through extensive experimentation, which includes matching of fretting risk areas, matching dynamic responses, and matching of fretting wipe lengths and location through image processing techniques.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"335 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123184752","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780001
S. Saha, R. Jackson
Closed-form finite-element empirical solutions are available for elastic-plastic spherical and sinusoidal contact. However, some of these models do not consider the effect of interaction with adjacent asperities or require extensive numerical resources because they employ a full 3-D model. The present work has considered these factors during modeling. The current finite element model (FEM) represents an axisymmetric elastic-plastic sinusoidal surface in contact with a rigid flat for a wide range of material properties and different values of the amplitude to wavelength ratio. The numerical results are compared with the existing elastic-plastic spherical contact model. Empirical equations are derived for the critical pressure at which two surface will reach complete contact. Complete contact occurs when there is no gap remaining between two contacting surfaces. An equation for the critical value of the amplitude of the sinusoidal asperity below which it will deform completely elastically from initial to complete contact is also established. The current study finds that for the cases which have amplitudes that fall below the critical value, and are elastic in nature, that the previously published perfectly elastic model can be used. The results are applicable for almost all kinds of metallic materials.
{"title":"Elastic-plastic axisymmetric sinusoidal surface asperity contact","authors":"S. Saha, R. Jackson","doi":"10.1109/HOLM.2016.7780001","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780001","url":null,"abstract":"Closed-form finite-element empirical solutions are available for elastic-plastic spherical and sinusoidal contact. However, some of these models do not consider the effect of interaction with adjacent asperities or require extensive numerical resources because they employ a full 3-D model. The present work has considered these factors during modeling. The current finite element model (FEM) represents an axisymmetric elastic-plastic sinusoidal surface in contact with a rigid flat for a wide range of material properties and different values of the amplitude to wavelength ratio. The numerical results are compared with the existing elastic-plastic spherical contact model. Empirical equations are derived for the critical pressure at which two surface will reach complete contact. Complete contact occurs when there is no gap remaining between two contacting surfaces. An equation for the critical value of the amplitude of the sinusoidal asperity below which it will deform completely elastically from initial to complete contact is also established. The current study finds that for the cases which have amplitudes that fall below the critical value, and are elastic in nature, that the previously published perfectly elastic model can be used. The results are applicable for almost all kinds of metallic materials.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123731774","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780026
Kai Bo, Xue Zhou, G. Zhai, Xinlei Qiao
Bridge-type contacts co-operated with permanent magnet are widely used in 270V/200A DC power relays. The permanent magnet helps to drive the arc out of contact gaps as soon as possible, and also helps to bend and quench the arc rapidly. Arc dwell stage is the first stage between arc ignition and the arc root moves out of the gap. This paper is focused on numerical investigation of dwell stage behaviors in bridge-type contacts in a 270V/200A DC power relay. A 2-D nitrogen arc model based on magneto-hydrodynamics theory is built and calculated. Basic dwell stage parameters are described by a set of coupled equations, including Navier-Stokes equation, energy equations and Maxwell equations. By adopting a floating potential, the voltage drop between movable contact and stationary contacts is solved. The detailed dwell stage behaviors are presented and preliminarily discussed according to the calculated temperature and arc current density distributions. Furthermore, experiments are carried out to validate the simulation results. The simulated arc voltage shows good agreement with that of acquired by experiments.
{"title":"Simulation on dwell stage of arcs in bridge type contacts for high-voltage DC relay","authors":"Kai Bo, Xue Zhou, G. Zhai, Xinlei Qiao","doi":"10.1109/HOLM.2016.7780026","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780026","url":null,"abstract":"Bridge-type contacts co-operated with permanent magnet are widely used in 270V/200A DC power relays. The permanent magnet helps to drive the arc out of contact gaps as soon as possible, and also helps to bend and quench the arc rapidly. Arc dwell stage is the first stage between arc ignition and the arc root moves out of the gap. This paper is focused on numerical investigation of dwell stage behaviors in bridge-type contacts in a 270V/200A DC power relay. A 2-D nitrogen arc model based on magneto-hydrodynamics theory is built and calculated. Basic dwell stage parameters are described by a set of coupled equations, including Navier-Stokes equation, energy equations and Maxwell equations. By adopting a floating potential, the voltage drop between movable contact and stationary contacts is solved. The detailed dwell stage behaviors are presented and preliminarily discussed according to the calculated temperature and arc current density distributions. Furthermore, experiments are carried out to validate the simulation results. The simulated arc voltage shows good agreement with that of acquired by experiments.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126391015","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780012
David M. Williams
Bolted busbar style connections on field installed power cords are common for high current electrical appliances mainly due to unique home appliance wiring which presents to the appliance either a three-wire or four-wire power outlet. This field installed situation creates an opportunity for significant variation which was the genesis for this study. A summary review of the applicable electrical joint theory related to the specific design adaptation of the bolted busbar under study is first reviewed. Then a wide inference space experimental investigation of human factors and variation sources is conducted to understand their effect on the junction tightness and contact resistance. Extrapolation of the findings in the study can be applied generally to any psychomechanical system where twist action tightness is accomplished through human haptic perception.
{"title":"Human factors affecting bolted busbar reliability","authors":"David M. Williams","doi":"10.1109/HOLM.2016.7780012","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780012","url":null,"abstract":"Bolted busbar style connections on field installed power cords are common for high current electrical appliances mainly due to unique home appliance wiring which presents to the appliance either a three-wire or four-wire power outlet. This field installed situation creates an opportunity for significant variation which was the genesis for this study. A summary review of the applicable electrical joint theory related to the specific design adaptation of the bolted busbar under study is first reviewed. Then a wide inference space experimental investigation of human factors and variation sources is conducted to understand their effect on the junction tightness and contact resistance. Extrapolation of the findings in the study can be applied generally to any psychomechanical system where twist action tightness is accomplished through human haptic perception.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121635819","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780019
D. Grogg, C. Schrank
The influence of the oxygen concentration on the break arc is observed in a range of 0 to 50 % oxygen in an oxygen-nitrogen mixture under a resistive DC load of 55.5 V and 10 Ω. The arc characteristics are observed by means of oscilloscope traces and high speed camera images showing a clear correlation of the arc motion and the speed of the motion with the oxygen concentration. In contrast, the electrical characteristics change only little over all gases containing oxygen and show a large difference for pure nitrogen. The motion of the arc on AgSnO2 and AgNi 0.15 is influenced in different ways by the higher oxygen concentration. The average distance between cathode spots (arc step) from frame to frame (observed at 483'000 images/s) is lowest for pure nitrogen for both materials. For AgSnO2, the arc step increases with increasing oxygen concentration at low oxygen levels and reaches a maximum step size at 15 to 20 % oxygen. For AgNi 0.15 larger arc steps are observed at 5 % oxygen, decreasing with increasing oxygen concentration over the whole range. These experiments show the importance of oxygen on the arc behavior and, therefore, on the relay behavior.
{"title":"Impact of the gas environment on the electric arc","authors":"D. Grogg, C. Schrank","doi":"10.1109/HOLM.2016.7780019","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780019","url":null,"abstract":"The influence of the oxygen concentration on the break arc is observed in a range of 0 to 50 % oxygen in an oxygen-nitrogen mixture under a resistive DC load of 55.5 V and 10 Ω. The arc characteristics are observed by means of oscilloscope traces and high speed camera images showing a clear correlation of the arc motion and the speed of the motion with the oxygen concentration. In contrast, the electrical characteristics change only little over all gases containing oxygen and show a large difference for pure nitrogen. The motion of the arc on AgSnO2 and AgNi 0.15 is influenced in different ways by the higher oxygen concentration. The average distance between cathode spots (arc step) from frame to frame (observed at 483'000 images/s) is lowest for pure nitrogen for both materials. For AgSnO2, the arc step increases with increasing oxygen concentration at low oxygen levels and reaches a maximum step size at 15 to 20 % oxygen. For AgNi 0.15 larger arc steps are observed at 5 % oxygen, decreasing with increasing oxygen concentration over the whole range. These experiments show the importance of oxygen on the arc behavior and, therefore, on the relay behavior.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116476658","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780006
E. Fjeld, W. Rondeel, M. Saxegaard
Air is a desirable alternative to the less environmental friendly SF6 in compact medium voltage switchgear. However, the poor thermal properties of air requires better thermal designs to keep the temperature rise within the allowable industry limits to avoid premature switch degradation. This publication focuses on the temperature rise of load break switches (LBS) of different designs. A LBS with flexible braid was found to have considerably higher temperature rise than a design with the sliding contact. The study has shown that a stripped switch (with only the current path) can be used together with empirical determined heat transfer coefficients in a first approach for predicting the temperature rise of the critical parts of the LBS. Aluminum construction elements functioning as heat sinks had a huge impact on the temperature rise of the LBS, and design elements that can utilize this might be important when replacing SF6 with air.
{"title":"Temperature rise in a load break switch","authors":"E. Fjeld, W. Rondeel, M. Saxegaard","doi":"10.1109/HOLM.2016.7780006","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780006","url":null,"abstract":"Air is a desirable alternative to the less environmental friendly SF6 in compact medium voltage switchgear. However, the poor thermal properties of air requires better thermal designs to keep the temperature rise within the allowable industry limits to avoid premature switch degradation. This publication focuses on the temperature rise of load break switches (LBS) of different designs. A LBS with flexible braid was found to have considerably higher temperature rise than a design with the sliding contact. The study has shown that a stripped switch (with only the current path) can be used together with empirical determined heat transfer coefficients in a first approach for predicting the temperature rise of the critical parts of the LBS. Aluminum construction elements functioning as heat sinks had a huge impact on the temperature rise of the LBS, and design elements that can utilize this might be important when replacing SF6 with air.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132381618","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}
Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780032
Junxing Chen, Fei Yang, K. Luo, Yi Wu, C. Niu, M. Rong
All engineering surfaces are of certain degree of roughness and comprising asperities of various size. When two rough surfaces contact with each other, the contact load will be dispersed by numerous contact spots generated by the compressive deformation of asperities. Weierstrass-Mandelbrot function is widely used in fractal contact theories to model the roughness and self-affinity of engineering surfaces. It is found that the fundamental assumptions in conventional fractal contact models are unsuitable for the description of true conditions. A numerical statistical method is utilized on the calculated fractal rough surfaces by W-M function to investigate the exact formulation of the size distribution function and profile function of asperities in fractal contact theories. Based on the statistical results presented, a modified three-dimension fractal contact theory is proposed.
{"title":"Study on contact spots of fractal rough surfaces based on three-dimensional Weierstrass-Mandelbrot function","authors":"Junxing Chen, Fei Yang, K. Luo, Yi Wu, C. Niu, M. Rong","doi":"10.1109/HOLM.2016.7780032","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780032","url":null,"abstract":"All engineering surfaces are of certain degree of roughness and comprising asperities of various size. When two rough surfaces contact with each other, the contact load will be dispersed by numerous contact spots generated by the compressive deformation of asperities. Weierstrass-Mandelbrot function is widely used in fractal contact theories to model the roughness and self-affinity of engineering surfaces. It is found that the fundamental assumptions in conventional fractal contact models are unsuitable for the description of true conditions. A numerical statistical method is utilized on the calculated fractal rough surfaces by W-M function to investigate the exact formulation of the size distribution function and profile function of asperities in fractal contact theories. Based on the statistical results presented, a modified three-dimension fractal contact theory is proposed.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130357993","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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