surface roughness & friction
surface roughness & friction
(OP)
Hallo everybody,
I have a little question: if I know the value of surface roughness (i.e value of Ra)can I derive the friction coefficient (like coulomb friction). I have to use some tables or formulations? Please show me how to find it(or the links to similar problems).
Thanks in advance.
I have a little question: if I know the value of surface roughness (i.e value of Ra)can I derive the friction coefficient (like coulomb friction). I have to use some tables or formulations? Please show me how to find it(or the links to similar problems).
Thanks in advance.





RE: surface roughness & friction
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: surface roughness & friction
Rz, load, speed and the specific material are all factors.
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Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: surface roughness & friction
Rough surfaces generally offer higher coefficient of friction due to mechanical locking and need for the asperities (peaks) of one surface to climb over the other. This is true for the initial sliding conditions and may be different once the surface gets "smoothened out" due to wear.
RE: surface roughness & friction
Tunalover
RE: surface roughness & friction
Interesting point to bring up. However I seem to recall way back in engineering basics (block sliding on a wedge) that it's only the weight of the block (or the normal force component) that is important and not the amount of surface are in contact.
RE: surface roughness & friction
Yes, I remember those simple mechanics problems. Then why aren't car tires as skinny as bicycle tires? Intuitively, a car tire that is twice as wide will stop a car faster will it not?
Tunalover