Tire Deformation outside contact patch
Tire Deformation outside contact patch
(OP)
Hello,
I have a question regarding tire deformation where I'm hoping someone could shed some insights. I'd like to get some understanding of the nature/magnitude of loaded tire deformation IN THE TREAD REGION (not on the sidewall) and OUTSIDE THE CONTACT PATCH. As I understand it (which may not be correct), tire engineers assume, at least as it applies to various tire engineering equations, that loaded tire deformation in this region (again - latitudinally not on the sidewall and circumferentially outside the contact patch) is zero or negligible. If it is 'negligible', could anyone give me some insights as to how negligible? Is it mm, tenths of mm's, tens of microns, etc?
Thanks for your help!
Graham
I have a question regarding tire deformation where I'm hoping someone could shed some insights. I'd like to get some understanding of the nature/magnitude of loaded tire deformation IN THE TREAD REGION (not on the sidewall) and OUTSIDE THE CONTACT PATCH. As I understand it (which may not be correct), tire engineers assume, at least as it applies to various tire engineering equations, that loaded tire deformation in this region (again - latitudinally not on the sidewall and circumferentially outside the contact patch) is zero or negligible. If it is 'negligible', could anyone give me some insights as to how negligible? Is it mm, tenths of mm's, tens of microns, etc?
Thanks for your help!
Graham





RE: Tire Deformation outside contact patch
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Tire Deformation outside contact patch
Second, the problem of what happens to the tread outside the footprint is even more complex than just the static deformation. There's a thing called a standing wave that appears on the trailing part of the tread surface - and it grows with speed.
On my web page on Tire Speed Ratings, I have some photos of standing waves:
Link
And magnitude? I think we are talking mm - at worse 10mm.
But why do you ask? Are you trying to closely fit something to the tire in this region?
RE: Tire Deformation outside contact patch
https://www.youtube.com/watch?v=E_u0YR10Vo0
or 0:50 here -
https://www.youtube.com/watch?v=lNjJaTt0hNw
or 1:20 here-
https://www.youtube.com/watch?v=mfJejgODr3E
RE: Tire Deformation outside contact patch
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Tire Deformation outside contact patch
The first video shows that standing wave quite clearly.
But the second and third videos show the tread buckling as it enters the footprint - something different than what this discussion is about.
RE: Tire Deformation outside contact patch
Looking for sources of rolling resistance and locations. Top of the tire is kinda weird, too.
RE: Tire Deformation outside contact patch
At the risk of derailing this thread:
Did your study determine that the belt causes the tread to bulge out at the ends of the footprint? Did the study determine that the tread "circumference" was essentially the same as the free standing circumference? Was it published somewhere?
BTW, if you want to continue this discussion elsewhere, email me at Barry@BarrysTireTech.com