NX minimum element lenght in "One-step formability"

In NX 11 It is possible to choose any Element size. Also a size lower than Thickness is accepted
 
 
 In NX 12 and NX 1872 it is no more possible to set an element size lower than thickness.
 
 

Solution

The use of elements which dimension is smaller then their thickness is strongly discouraged. The constitutive laws of the elements work best when the ratio between dimension and thickness is quite high, 10 should be the lower limit for that ratio. I.e. for a thickness of 1 mm the element dimension should be not less than 10 mm. 
One-step solver is based on thin-plate theory, creating two-dimensional elements, using Finite Element Method (FEM) to solve linear elastic and non-linear plastic equations on sheet metal stamping forming process. It's dependent on the material property, thickness, draw direction, boundary constraints etc. inputs. The thin-plate theory assumes that a mid-surface can be used to represent a three-dimensional plate in two-dimensional form. It means the thickness is very, very small relative to 2D dimensions, the mesh element size has to be greater than thickness, as an extreme limit. By creating elements which dimensions do not respect this limit, the obtained results will be unrealistic. A validation was added to the software to ensure the solver would produce reasonable results.
 

Hardware/Software Configuration

Platform: all
OS: n/a
OS Version: n/a
Product: NX
Application: DESIGN
Version: V12.0
Function: INFO_ANALYSIS

Ref: 002-8171449