I defined several materials; SHAPE-THIN determines strange cross-section properties.
For cross-section with several material, the ideal cross-section properties and cross-section diagrams are determined.
For this, the reference material defined in the General Data under [Settings] is used.
Thus, the surface of the individual materials is recalculated to the surface of the reference material by using:
n = E_i / E_ref.
Cross-Section Properties Software
Section properties, stress analysis, and plastic design of open and closed thin-walled cross-sections