Alexcy

quick update: After further investigation, I concluded the following: Etabs considers the stiffness of the connected members in order to determine the level of fixity. This can be easily verified by modeling multiple portal frames with the same beam size and different column sizes. Shell elements without mesh have a high artificial stiffness that is not representative and is unrealistic. In addition, i came across an ETABS manual by Atkins, where they recommend the following : If the shell element (wall) has a refined mesh, consider extending the beam into the wall at least one shell element to model proper fixity.

Hello, I have tested a frame in etabs with multiple variations. The portal frame is the exact same dimensions in all cases, with the only difference being that the wall mesh is getting smaller/finer each time. The Shell dimensions are 250x1000mm in all cases and the beam size is 250x500mm. Can someone explain to me how the mesh of the shell element affect the beam? I did not assign any releases to the beam but as the mesh gets smaller it looks like the beam is simply supported. ETABS.pdf