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Old October 17th 04, 07:45 PM
Haqsau
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For the static weight distribution yes, the location matters, but for
dynamic weight *transfer* only the height of the cg matters. This is under
the assumption that you have already resolved the lateral and longitudinal
forces so that they are truly orthogonal to each other and to the vertical
direction. It is this relationship of the forces that allows you to assume
that the car's opposing force is acting through the cg and parallel to the
ground.

I'm not sure why you are trying to account for non-rectangular wheel
locations when you aren't accounting for suspension deflection. I thought
you were trying to keep it simple. )

If you for example resolve the roll moments and lateral forces into the yz
plane, i.e. looking at the vehicle from the rear, unequal track width means
you now have 2 moments opposing the roll moment. In order to solve this you
need an equation relating the two moments to each other. The normal way of
doing this is to include the deflection characteristics of the suspension
and chassis, as others have mentioned.

So if you really are just trying to do a simple 2D problem and ignore
deflections you should probably also keep the wheels in a rectangular
arrangement so that the problem is solvable under the constraints you are
using.

"Ruben" > wrote in message
m...
>
> I don't think I understand how you arrive at this. Doesn't it matter
> where the centre of mass is located - apart from its height?
>
> Also, this is assuming the wheels are in a rectangle, which may not be
> the case. If you are being accurate about steering, then the wheels
> rotate about a point which is external to the wheel. Also, the front
> and rear track may be different.
>
> Ruben



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