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Unread 03-07-2008, 13:22
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AKA: Mark Kramarczyk
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Re: 6WD Chassis Stiffness vs. Maneuverability

A low CG certainly does help you withstand higher turning moments, but it does not help you generate them.

For those that have read Chris Hibner's whitepaper on turning (http://www.chiefdelphi.com/media/papers/1443), which is everybody I hope, it looks at the individual contribution of each wheel to the turning moment, so I suggest we start here. The moment is generated at each wheel by the coefficient of friction (CoF) and normal force (Fn) at each wheel. I think that the CoF is largely understood as demonstrated by the unusual wheel choices cited above. So what changes the Fn at each wheel? Simplifing the frame as a series of beams for discussion we can reference some stock solutions for the beams with 3 supports; based upon a uniform load the 3 moment equations show that the center axle would support 62.5% of the load with 18.75% for the outer axles. A snapshot of this eqn is in a previous post here.
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