Modeling of Friction in RFEM6

[AlexITI]

Topic Friction in RFEM6,

We are currently conducting orientation tests to determine the coefficient of friction of CLT elements.
I am modeling the physical tests in RFEM6 and trying to obtain the measured values correspondingly through the numerical approach.
I encountered the following problem:
V1) As a multilayer surface model, friction representation works quite well, but I do not get any information about the shear stresses in the core layer. These are of particular importance due to roll shear failure of individual CLT lamellas.

V2) As a volume model, I do get the shear stresses, but I cannot represent friction through the type "surface contacts" because both friction surfaces lie in one plane, causing the corresponding error message to appear.

Can someone help me with this problem?

[eike.hartmann]

Thank you very much for your detailed description.

The behavior in the volume model is related to the fact that surface contacts in RFEM cannot be defined if both contact surfaces lie exactly in the same plane.

To circumvent this, there are two possible approaches:

• Introducing a minimal geometric distance between the contact surfaces
• Alternatively, using surface releases

From my point of view, the approach with a very small distance is preferable. This allows targeted control of the decoupling. When using surface releases, the verification is somewhat more complex, especially checking whether nodes and lines have been correctly released.

I hope this helps you further. If you have any questions, please feel free to contact me.