Why is the shear stiffness reduced to 10% in the RF‑LAMINATE add-on module as well as for the orthotropic material model in RFEM for the shear modulus Gyz? I think the shear stiffness in the shear plane Gxy would have to be reduced here?


The reduction of the shear stiffness is caused by the fact that the fibers perpendicular to each other have a very small stiffness and a low strength. For this reason, the rolling shear strength of CLT panels is also very small.

In the case of cross-laminated timber plates, the glued sideboards are assumed on the boards. The boards are applied in the longitudinal direction along the x‑axis of the coordinate system (Figure 02). For the shear stresses in Figure 02, the shear stress τyz is thus opposed to the rolling shear strength.

The same applies to the shear stiffnesses. In the direction of the minor axis (yz‑ plane), the stiffness of the individual boards is considerably smaller than in the direction of the principal axis (xz‑plane) and also larger than in the xy‑plane. The coordinate system shown in Figure 02 should be placed on the boards in Figure 03.


Boards Sideboards Stiffness Rolling shear


Contact us

Contact to Dlubal

Did you find your question?
If not, contact us via our free e-mail, chat, or forum support, or send us your question via the online form.

+49 9673 9203 0


RFEM Main Program
RFEM 5.xx

Main Program

Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements

Price of First License
3,540.00 USD
RFEM Other

Add-on Module

Deflection analysis and stress design of laminate and sandwich surfaces

Price of First License
1,120.00 USD