I am meshing a part using NX9.0. I defined some User Defined expressions (Type: number, Unit: mm) which describe the size of the element that I want to apply. Then I refered the Software Expressions to these User Defined ones when I defined the mesh control. The purpose was to update the mesh control automatically once I modified the values of the User Defined expressions.
The problem was when I re-opened the mesh control dialog box after the definition, the software expression became a constant and the reference to the user defined expression seemed don't exist anymore (as shown in the right pic). I have re-defined this reference for many times but it was still the same problem once I re-opened the mesh control dialog box. The weirdest thing was that this problem only happened to some of the mesh controls that I defined, all the others worked fine.
I also had similar issues when I defined the offset of the shell element using User Defined expressions.
Can anyone help me figure out what's the reason for this?
Before clicking "OK" After re-opening of the dialog box