Michelin problems at Indy 2005

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flynfrog
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Re: Michelin problems at Indy 2005

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WhiteBlue wrote:
Michelin officially blames special dynamic effects of turn 13 to generate loads far superior to the maximum estimation of their engineers.

What do you think was this special dynamic effect if it wasn't resonance?
how about the increased load that a banked corner places on the outer shoulder of tire? Its amazing how you can read anything to fit your pre drawn conclusion.

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strad
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Re: Michelin problems at Indy 2005

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Gas pressure supports load

Don't start this again...It is not the gas that supports the load and adding pressure doesn't act as increasing the spring rate...at least according to our resident experts. :wink:
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hardingfv32
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Re: Michelin problems at Indy 2005

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How far down the sidewall could one expect the steel band mentioned in the Michelin tire? I have never seen the steel belt extend beyond the thread width.

Does steel have better properties than aramid synthetic fibers? Seems an odd choice where cost is a low priority.

Brian

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WhiteBlue
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Re: Michelin problems at Indy 2005

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flynfrog wrote:
WhiteBlue wrote:
Michelin officially blames special dynamic effects of turn 13 to generate loads far superior to the maximum estimation of their engineers.

What do you think was this special dynamic effect if it wasn't resonance?
how about the increased load that a banked corner places on the outer shoulder of tire? Its amazing how you can read anything to fit your pre drawn conclusion.
The increased load that a banked corner places on the outer shoulder of a tire isn't special at all and would not have been overlooked by Michelin. They knew the track from years ago and they knew the downforce their customer teams produced that year. They knew the speeds probably down to 3-5 kph. They even knew how different cars would use the tyres differently. How could they fail to take something so simple into account in their physical model.

The one thing they did not know and could not foresee was the lateral oscillation which Michelin called bobbing and that occurred on the side wall. That was the only special physical effect.
Formula One's fundamental ethos is about success coming to those with the most ingenious engineering and best .............................. organization, not to those with the biggest budget. (Dave Richards)

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WhiteBlue
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Re: Michelin problems at Indy 2005

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strad wrote:
Gas pressure supports load
.. It is not the gas that supports the load and adding pressure doesn't act as increasing the spring rate...
Sometimes you hit the nail on the head. Different tyre pressure was never a parameter to the solution of the Indy 2005 problem. Even if we assume that the tyre is a non linear spring damper system the spring rate would not change drastically enough in the small pressure range of an F1 operating window to avoid a resonance if they designed an Eigen frequency into that range.
Formula One's fundamental ethos is about success coming to those with the most ingenious engineering and best .............................. organization, not to those with the biggest budget. (Dave Richards)

hardingfv32
hardingfv32
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Re: Michelin problems at Indy 2005

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1) Why the much higher tire pressure used by oval formula cars?

2) I think that turn 13 at Indy had very different requirements than the other 12 (?) turns. What was required for turn 13 was very bad for the other 12. Could it be that Michelin just made a wrong aggressive compromise?

Brian

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FW17
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Re: Michelin problems at Indy 2005

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WhiteBlue wrote:
The one thing they did not know and could not foresee was the lateral oscillation which Michelin called bobbing and that occurred on the side wall. That was the only special physical effect.
What caused this lateral oscillation?

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flynfrog
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Re: Michelin problems at Indy 2005

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WhiteBlue wrote:
flynfrog wrote:
WhiteBlue wrote:
Michelin officially blames special dynamic effects of turn 13 to generate loads far superior to the maximum estimation of their engineers.

What do you think was this special dynamic effect if it wasn't resonance?
how about the increased load that a banked corner places on the outer shoulder of tire? Its amazing how you can read anything to fit your pre drawn conclusion.
The increased load that a banked corner places on the outer shoulder of a tire isn't special at all and would not have been overlooked by Michelin. They knew the track from years ago and they knew the downforce their customer teams produced that year. They knew the speeds probably down to 3-5 kph. They even knew how different cars would use the tyres differently. How could they fail to take something so simple into account in their physical model.

The one thing they did not know and could not foresee was the lateral oscillation which Michelin called bobbing and that occurred on the side wall. That was the only special physical effect.
the fact that corner has way more banking than any other corner in F1 id say that would be a special dynamic situation.

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WhiteBlue
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Re: Michelin problems at Indy 2005

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WilliamsF1 wrote:
WhiteBlue wrote:
The one thing they did not know and could not foresee was the lateral oscillation which Michelin called bobbing and that occurred on the side wall. That was the only special physical effect.
What caused this lateral oscillation?
resonance
Formula One's fundamental ethos is about success coming to those with the most ingenious engineering and best .............................. organization, not to those with the biggest budget. (Dave Richards)

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WhiteBlue
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Re: Michelin problems at Indy 2005

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flynfrog wrote:
WhiteBlue wrote:
flynfrog wrote:how about the increased load that a banked corner places on the outer shoulder of tire? Its amazing how you can read anything to fit your pre drawn conclusion.
The increased load that a banked corner places on the outer shoulder of a tire isn't special at all and would not have been overlooked by Michelin. They knew the track from years ago and they knew the downforce their customer teams produced that year. They knew the speeds probably down to 3-5 kph. They even knew how different cars would use the tyres differently. How could they fail to take something so simple into account in their physical model.

The one thing they did not know and could not foresee was the lateral oscillation which Michelin called bobbing and that occurred on the side wall. That was the only special physical effect.
the fact that corner has way more banking than any other corner in F1 id say that would be a special dynamic situation.
Come on! How would that affect a physical model of the dynamic forces? Not at all!! You simply dial in higher forces with more banking. To create an additional new load you have to assume that a new effect was introduced and not a gradual increas of existing loads.
Formula One's fundamental ethos is about success coming to those with the most ingenious engineering and best .............................. organization, not to those with the biggest budget. (Dave Richards)