This title appears in the Scientific Report :
2018
Please use the identifier:
http://dx.doi.org/10.1063/1.5037136 in citations.
Please use the identifier: http://hdl.handle.net/2128/21541 in citations.
Rubber friction: The contribution from the area of real contact
Rubber friction: The contribution from the area of real contact
There are two contributions to the friction force when a rubber block is sliding on a hard and rough substrate surface, namely, a contribution Fad = τf A from the area of real contact A and a viscoelastic contribution Fvisc from the pulsating forces exerted by the substrate asperities on the rubber...
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Personal Name(s): | Tiwari, A. (Corresponding author) |
---|---|
Miyashita, N. / Espallargas, N. / Persson, Bo | |
Contributing Institute: |
Quanten-Theorie der Materialien; IAS-1 JARA - HPC; JARA-HPC JARA-FIT; JARA-FIT Quanten-Theorie der Materialien; PGI-1 |
Published in: | The journal of chemical physics, 148 (2018) 22, S. 224701 |
Imprint: |
Melville, NY
American Institute of Physics
2018
|
DOI: |
10.1063/1.5037136 |
PubMed ID: |
29907043 |
Document Type: |
Journal Article |
Research Program: |
Controlling Electron Charge-Based Phenomena |
Link: |
Published on 2018-06-12. Available in OpenAccess from 2019-06-12. Published on 2018-06-12. Available in OpenAccess from 2019-06-12. |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/21541 in citations.
There are two contributions to the friction force when a rubber block is sliding on a hard and rough substrate surface, namely, a contribution Fad = τf A from the area of real contact A and a viscoelastic contribution Fvisc from the pulsating forces exerted by the substrate asperities on the rubber block. Here we present experimental results obtained at different sliding speeds and temperatures, and we show that the temperature dependency of the shear stress τf, for temperatures above the rubber glass transition temperature Tg, is weaker than that of the bulk viscoelastic modulus. The physical origin of τf for T > Tg is discussed, and we propose that its temperature dependency is determined by the rubber molecule segment mobility at the sliding interface, which is higher than in the bulk because of increased free-volume effect due to the short-wavelength surface roughness. This is consistent with the often observed reduction in the glass transition temperature in nanometer-thick surface layers of glassy polymers. For temperatures T < Tg, the shear stress τf is nearly velocity independent and of similar magnitude as observed for glassy polymers such as PMMA or polyethylene. In this case, the rubber undergoes plastic deformations in the asperity contact regions and the contact area is determined by the rubber penetration hardness. For this case, we propose that the frictional shear stress is due to slip at the interface between the rubber and a transfer film adsorbed on the concrete surface |