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Can you calculate torsional constant in AutoCad?

Can you calculate torsional constant in AutoCad?

Can you calculate torsional constant in AutoCad?

(OP)
I am familiar with massprop.
Can AutoCad calculate the torsional constant, J?

RE: Can you calculate torsional constant in AutoCad?

Your J value is just the sum of Ix and Iy which you will get when invoking the command LI on solids

RE: Can you calculate torsional constant in AutoCad?

The sum or the root of the squares?  Been so long, I've forgotten (second thing to go is the memory) <g>

dik

RE: Can you calculate torsional constant in AutoCad?

(OP)
That J is the polar moment of inertia which is different from Torsional Constant

RE: Can you calculate torsional constant in AutoCad?

I am so use to using J as the polar moment of inertia and not as the torsional constant that my answer was not was you were looking for.  Since torsional constant is in essence a polar moment of inertia calculation, you can still apply the region/mass property command and use the J value with a slight error.  For circular thin wall tubing that error will be of a magnitude( ie, slightly higher value)of (pie*R*t^3)/2. Note t^3 is very small for thin wall tubing.  For circular thin wall tubing the polar constant is 2*pie*t*R^3 and the polar moment of inertia will sligthly higher by the error value that I mentioned.

RE: Can you calculate torsional constant in AutoCad?

(OP)
I dont think torsional constant can replace polar moment of inertia. even for simple rectangular tube the difference is in the magnitude of 400%. I am however not familiar with solids.

RE: Can you calculate torsional constant in AutoCad?

Yes, you are correct, I rechecked my calculations on a couple of exercises and values for torsional constant were greater than the polar moment values.

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