Answer:
In RF‑GLASS, there are two different types of calculations. On one hand, there is the "2D" calculation. In this case, a glass structure is displayed as a surface element. When considering shear coupling, the program determines an equivalent cross-section using the laminate theory. On the other hand, there is the "3D" calculation. In this case, the composition is modeled as a solid element in the calculation, and thus the effectiveness of stiffnesses between the foil and glass is determined precisely when considering the coupling.
Further information about the calculation methods can be found in the RF‑GLASS manual, Chapter 2.
