Contact Measurements of Randomly Rough SurfacesShow others and affiliations
2017 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 65, no 4, article id 134Article in journal (Refereed) Published
Abstract [en]
This manuscript presents an experimental effort to directly measure contact areas and the details behind these scaled experiments on a randomly rough model surface used in the “Contact Mechanics Challenge” (2017). For these experiments, the randomly rough surface model was scaled up by a factor of 1000× to give a 100 mm square sample that was 3D printed from opaque polymethylmethacrylate (PMMA). This sample was loaded against various optically smooth and transparent samples of PDMS that were approximately 15 mm thick and had a range in elastic modulus from 14 kPa to 2.1 MPa. During loading, a digital camera recorded contact locations by imaging the scattering of light that occurs off of the PMMA rough surface when it was in contact with the PDMS substrate. This method of illuminating contact areas is called frustrated total internal reflection and is performed by creating a condition of total internal reflection within the unperturbed PDMS samples. Contact or deformation of the surface results in light being diffusely transmitted from the PDMS and detected by the camera. For these experiments, a range of reduced pressure (nominal pressure/elastic modulus) from below 0.001 to over 1.0 was examined, and the resulting relative contact area (real area of contact/apparent area of contact) was found to increase from below 0.1% to over 60% at the highest pressures. The experimental uncertainties associated with experiments are discussed, and the results are compared to the numerical results from the simulation solution to the “Contact Mechanics Challenge.” The simulation results and experimental results of the relative contact areas as a function of reduced pressure are in agreement (within experimental uncertainties).
Place, publisher, year, edition, pages
Springer Science and Business Media, LLC , 2017. Vol. 65, no 4, article id 134
Keywords [en]
Contact Mechanics Challenge, Contact of rough surfaces, Measurements of real area of contact, 3D printers, Deformation, Microchannels, Refractive index, Contact measurements, Contact Mechanics, Contact of rough surface, Experimental uncertainty, Frustrated total internal reflections, Randomly rough surfaces, Real area of contact, Total internal reflections, Surface measurement
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
URN: urn:nbn:se:ri:diva-56329DOI: 10.1007/s11249-017-0918-5Scopus ID: 2-s2.0-85028755465OAI: oai:DiVA.org:ri-56329DiVA, id: diva2:1591326
2021-09-062021-09-062023-05-23Bibliographically approved