Standard Guide for Determination of Static Coefficient of Friction of Test Couples Using an Inclined Plane Testing Device

10.1520/g0219 ◽  
2019 ◽  
Author(s):  
Keyword(s):  
Coefficient Of Friction ◽  
Testing Device ◽  
Inclined Plane ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

Effect of the angle of the laid-up filaments on the surfaces on the coefficient of static friction between parts manufactured by extrusion-based 3D printing

2020 ◽  
pp. 146442072097899
Author(s):  
Leonardo Santana ◽  
Jorge Lino Alves ◽  
Aurélio da Costa Sabino Netto
Keyword(s):  
Lactic Acid ◽  
Ethylene Glycol ◽  
Coefficient Of Friction ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Insertion Force ◽  
Inclined Plane ◽  
Poly Ethylene ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

Three-dimensional printers, particularly the extrusion-based ones, are driving a global academic, industrial, and social revolution. The accessibility of the technology has allowed a number of enthusiasts and scientists to dedicate efforts to improve the technical properties of the parts produced. However, there is little literature on the measurement of the coefficient of friction, especially the static one, between a pair of printed parts. In this sense, an investigation was carried out in two stages, in which at first the static coefficient of friction was measured, through a simple apparatus based on the concept of the inclined plane, varying the angle of the filaments laid up on the surfaces of the two parts in contact. The parameter was analyzed at three levels—0°, 45°, and 90°—in components manufactured in poly(lactic acid) and poly(ethylene glycol terephthalate). In the second part of the research, a case study was carried out to test and validate the effects of the best and worst friction conditions on the behavior of the insertion force of snap-fit connections. The results obtained show a significant influence of the filament angle in the interaction between two printed parts. Combinations of contact with different angles decrease the static coefficient of friction, while faces with equal angles tend to increase the magnitude of the response, especially if the arrangement of the filaments allows a fit of the surfaces opposite to sliding. The static coefficient of friction of poly(lactic acid) varied from 0.12 to 0.38, while the static coefficient of friction of poly(ethylene glycol terephthalate) varied from 0.13 to 0.21. The responses of the inclined plane test allowed to predict the behavior of the insertion force and plan the design of quick fittings.

Determining the Coefficient of Friction for Rolling Disks

1978 ◽  
Vol 100 (1) ◽  
pp. 25-30
Author(s):  
D. H. Offner ◽  
N. Tomita
Keyword(s):  
Potential Energy ◽  
Coefficient Of Friction ◽  
Surface Deformation ◽  
Empirical Relationship ◽  
Rolling Resistance ◽  
Experimental Results ◽  
Testing Device ◽  
The Coefficient Of Friction ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

A method and testing device for determining a coefficient of friction for rolling disks is described. The method equates the energy of rolling resistance to the change in potential energy of a moving system. The experimental results of applying this method to steel, aluminum, and plexiglass disks of 3.8, 2.5, and 1.7 cm radii and 1 cm width rolling on steel and aluminum bases are summarized. An empirical relationship between the coefficient of friction and energy of surface deformation is presented. Use of device for determining the static coefficient of friction for impending rolling and sliding of disks is discussed.

scholarly journals DETERMINING THE COEFFICIENT OF FRICTION OF WOOD-BASED MATERALS FOR FURNITURE PANELS IN THE ASPECT OF MODELLING THEIR SHREDDING PROCESS

Wood Research ◽  
2021 ◽  
Vol 66 (5) ◽  
pp. 789-805
Author(s):  
MATEUSZ KUKLA ◽  
ŁUKASZ WARGUŁA ◽  
ALEKSANDRA BISZCZANIK
Keyword(s):  
Coefficient Of Friction ◽  
Kinetic Coefficient ◽  
Drive Unit ◽  
Base Surface ◽  
The Coefficient Of Friction ◽  
Kinematic Coefficient ◽  
Cutting Processes ◽  
Static Coefficient Of Friction ◽  
Static Coefficient ◽  
Selection Of

In order to improve the power selection of the drive unit for the shredding machines,theauthors determine the values of friction coefficients used in the cutting force models. These values consider the friction between steel and such wood-based materials as chipboard, MDF and OSB. The tests concern laminated and non-laminated external surfaces and surfaces subjected to cutting processes. The value of the coefficient of friction for the tested materials is in the range: for the static coefficient of friction 0.77-0.33, and for the kinetic coefficient of friction 0.68-0.25. The highest values of the static and kinematic coefficient of friction were recorded for MDF (non-laminated external surface) and they were equal respectively: 0.77 and 0.68. In turn, thesmallest values of the discussed coefficients were recorded for chipboard (laminated external wood-base surface), which were at the level of 0.33 and 0.25, resp.

scholarly journals Measuring the Static Coefficient of Friction of Non-Fluid Contaminants

2019 ◽  
Vol 63 (1) ◽  
pp. 537-541
Author(s):  
Hunter DeBusk ◽  
Levi Dixon ◽  
Joellen Gill ◽  
Richard Gill
Keyword(s):  
Coefficient Of Friction ◽  
Human Subjects ◽  
Small Samples ◽  
Subjective Ratings ◽  
Slip Event ◽  
Materials Used ◽  
Static Coefficient Of Friction ◽  
Static Coefficient ◽  
Porcelain Tile ◽  
Floor Material

The purpose of our study was to evaluate whether there are differences between measuring the static coefficient of friction (SCOF) of a non-fluid contaminant when it is directly attached to a tribometer test foot, or “Attached”, versus when it is lying loose on the floor, or “Loose”. The non-fluid materials used in this study included Mylar, Cardboard, Terrycloth Bathmat, and Terrycloth Bathmat with Rubberized Silicon Backing; the floor material was porcelain tile. In addition, 10 participants subjectively rated the “slipperiness” of each material by pushing the materials with one foot across the porcelain tile. The findings of this study revealed that within each technique, Attached and Loose, the measurements were consistent and reliable. Furthermore, both techniques resulted in identical ordering of the materials from lowest to highest SCOF, which was verified by the human subjects’ subjective ratings of slipperiness. However, the Loose technique SCOF values were slightly but consistently greater than the Attached technique SCOF values; the Loose tests of the entire bathmats were found to have greater SCOF values when compared to Loose tests of small samples. These findings suggest that when investigating a specific slip event, a practitioner should measure the SCOF of the non-fluid contaminant using the technique which most closely represents the conditions of the slip event.

Testing the Validity of Greenwood and Tripp’s Sum Surface Assumption for Elastic-Plastic Contact

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Ashutosh Roy ◽  
Bhargava Sista ◽  
Kumar Vemaganti
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Correlation Length ◽  
Coefficient Of Friction ◽  
Rough Surfaces ◽  
Surface Model ◽  
Finite Element Models ◽  
Rigid Plane ◽  
Static Coefficient Of Friction ◽  
Static Coefficient

Abstract The complexity of modeling friction between rough surfaces has prompted many researchers to use Greenwood and Tripp’s sum surface assumption to simplify the analysis. This assumption approximates the contact between two rough surfaces as contact between their equivalent sum surface and a rigid plane. In this work, we develop detailed finite element models to test the sum surface assumption for surfaces with Gaussian and exponential autocorrelation functions. We consider surfaces with differing surface roughness and correlation length values. For each case, we conduct simulations of two rough surfaces interacting in compression followed by shear, and a corresponding equivalent surface model based on the sum surface assumption. Multiple realizations of each parameter combination are simulated to obtain a statistical picture of the responses. We find that (a) the sum surface assumption consistently under-predicts the static coefficient of friction and (b) the equivalent surface model is less accurate for surfaces with differing correlation length-to-surface roughness ratios.

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