Answer:
If the fabric is modeled as directly attached to the supporting beam, it is treated as continuously connected to the member. This assumption is appropriate only when the fabric is fully secured along its length. In many cases, however, the fabric simply rests on the member without being attached.
To allow fabric to slide in RFEM 6, add in Rigid members. Next, activate the hinges within the rigid member type and release them in the uy and uz directions. Next, activate the member nonlinearity and select "Failure if tension" to fail in uplift.
Do not add member hinges and nonlinearities at the “corners” to avoid instability.
The rigid links are spaced 1 ft apart to coincide with the FE mesh length.
