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I need an estimate for the polar moment of inertia

I need an estimate for the polar moment of inertia

I need an estimate for the polar moment of inertia

(OP)
Folks,

I need to estimate the pitch moment of inertia of a vehicle for Vehicle Sim.

I have the corner weights as well as track and wheelbase.  My first thought was to treat the vehicle as a dumbell with two different size masses.

The pitch moment would be the sum of the mr2 with r being the distance between the cg and the front and rear axles respectively.

Any ideas.

Jim

RE: I need an estimate for the polar moment of inertia

That's not a bad approach, rule of thumb is that it is the same as the yaw inertia, or a bit less, and the NHTSA publishes a list. Sorry haven't got the link.

Cheers

Greg Locock

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RE: I need an estimate for the polar moment of inertia

What's the vehicle? Maybe its laying aroung here.  Other option is to easure it yourself...

RE: I need an estimate for the polar moment of inertia

The corner weights and track wheelbase are not enough to determine pitch moment. E.g. a mid engined car might have a far lower pitch moment for the same corner weights than a front or rear engined car.

Pete.

RE: I need an estimate for the polar moment of inertia

(OP)
Thanks everyone.  I fully understand that I don't have enough to determine the polar moment.  I was hoping someone had a good rule of thumb.

I do have the NHTSA paper with their data and some of it seems a little off with respect to weights.

Thanks anyway.

Jim

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