NEW MATERIAL PROPERTY (V/MM) NOT PRESENT IN THE UNITS DROP DOWN LIST

[AndreaM]

I am using Creo Parametric - Release 7.0 (connected) 7.0 7.0.1.0

I would like to add a material property called DIELECTRIC BREACKDOWN VOLTAGE, units are [kV/mm].
When I add this feature to MATERIAL USER DEFINED features tab, I cannot select this unirs from the drop down list because it is not present.
Is there a way to add a few units to that list?

[AndreaM]

I'm attaching here the tab/list I'm referring to.

Thank you!

[KenFarley]

If you want to define a new unit of measure you need to do the following (Creo 4):

Execute the menu picks

File -> Prepare -> Model Properties
Units -> Change
Units -> New...

This brings up the units definition dialog. Select “Derived” from the Physical Dimension list, and enter the definition of your unit of measure. The "Numerical Unit Expression" must be a combination of known units, as Creo will only accept units of measure that it “knows”. For example, “m^2” is not the same as “M^2”, etc. Once the new unit definition is done, it can be assigned to parameters. Hopefully "kV" is a known unit of measure for your particular case, you'll have to check and might find it is something like "kilovolt" or "kVolt", etc.

[AndreaM]

Thank you for your explanation.

I have followed it and tried, but it seems CREO 7 does not recognise V, or any other potential name.

I tried to define it (see attached new_unit_2.png) but there is no way to do that because it does not recognise Ampere either (see attached new_unit_1.png).

Following the instructions below:

File -> Prepare -> Model Properties

Units -> Change

System of Units -> Info

a text file appears listing (I think) all/most of the units recognised. Unfortunately, I cannot see any reference to Volts, Amperes, Ohm, etx., so, it seems it will not allow me to add an electrical-related units.

Is that possible?

[KenFarley]

I don't know if anyone else has an idea, but it seems that there isn't any way to define electrical units. There's a Watt in the standard units, but not enough standard units to define a Volt. Seems to be a bias towards thermal and physical units. Maybe a custom system of units would let you define your own "basic" units? I don't know - it's not something I've ever had to attack.

[kdirth]

There is a units.sup file in the install directory that defines all of the units in Creo.  Might be a bit dangerous trying to add and define new units in this file.  Keep a backup of the original if you do. 

Creating a units.pro file might also work to add new units without changing the units.sup file.  Place it in your default working directory.

Again, I do not know if this is safe or even a supported modification.

[AndreaM]

Thank you all for your answers.

I "weakly" tried to modify the units unsuccesfully.

However, since it seems to be a little dangerous, at the moment we decided not to add any electric-related features/units to the part.

[KenFarley · Accepted solution]

I took a cursory attempt at a units.pro file, just containing the volt,kV,V,mV units to add. I copied the units.sup and followed the formatting and syntax it uses.

The end result was: no change. The voltage unit additions don't show up. Either I botched something up, or the units.pro file is not something Creo is loading at startup. I didn't mess about with the units.sup file.

[AndreaM]

Thanks, I have also tried to do something similar as you have, with the same results: no changes.

I can assume now there is no way (so far) this can be done.