Polar moment of inertia as a model parameter

What part of the process are you having trouble with?

Presumably you have some parameter that you need to give to MathCAD, probably a floating value? You can calculate that with a relation based upon saved mass properties.

If you're having difficulties with calculating the polar moment of inertia, you could search for other discussions of that particular model property, and get results like this:

Polar Inertia Discussion

From a quick perusal of this I see two key things you need to understand:

(1) Where is the moment of inertia being calculated around? An axis? A particular coordinate system? This will be the fun mathematical part of the endeavor. Hopefully a saved analysis will give you all the model properties you need to do the calculations.

(2) How to save an analysis and subsequently access its values in equations. There are a lot of discussions of this out there, too. I do this on a somewhat infrequent basis, and usually just search for it when I'm unsure of the syntax and steps involved. Like a lot of Creo stuff, it's not particularly intuitive, but then again, provides amazing functionality once implemented.

I don't recall a mass properties analysis making any parameters (measurements do, but polar moment of inertia is not one of them,) but it does create a .inf file, which is plain text. MathCAD should be able to extract a value from that text file.

An alternative is to create a mapkey that runs a script to generate the .inf file, runs an external program to extract the value from the .inf file, and then generate a further mapkey that sets the value of a parameter equal to the inertia, and finally runs that mapkey to create/update the parameter.

It's also possible that one could use a program like AutoIt to monitor the output area for .inf files and, when one shows up that includes inertia values, it creates a mapkey to do the assignment, allowing the user the choice of when to run it.

Perhaps there's a more direct route, but I don't know of it.