Portal frame 2023

This example shows how to build a FEM analysis model for a portal frame illustrated in the figure below. The bottom ends of columns will be fixed to the ground. The top chords of the frame are loaded with linear load. The self-weight of profiles is also taken into account.

Create a new study

1. Open model Ex_FEA_Beam_2 from project Examples. Go to FEA state by selecting FEA >  FEA for Beams and Frames from contextual menu.
   
   
   
2. Select all parts of the model and create a new study by pressing  New study from ribbon tab.
   
   
   
3. Fill study information. Set Self-weight of profiles selected.

Link nodes

1. Select all parts of the study by pressing Select parts from the contextual menu of the active study in study tree.
   
   
   
2. Link the nodes of selected parts by pressing Link from the contextual tab.
   
   
   
3. Set the tolerance to Automatic. The tolerance will be calculated automatically based on the cross sections of selected parts. Set the connection between nodes as Fully connected. The connections between parts will be rigid. Link nodes by pressing OK.
   
   
   
4. The profiles of frame are now linked. The joint parts of model are not included in the study because they are not valid sources for beam elements. Let's assume that the joint parts have same mechanical behaviour as top chords of the frame. Extend the chords in the analysis model by adding extra elements to them. Select a chord and press Insert node from contextual tab. Add node to the extension of chord under the point where joint part's axis of rotation is located.
   
   
   
   

5. Select nodes and press Link from contextual menu. Set  Hinged about axis Z as connection between nodes. Press OK. Repeat this process to all end nodes of extended chords.

   Visible and selectable nodes can be filtered by selecting parts of active study. Only nodes belonging to selected parts are visible and selectable

   

Set supports and loads

1. Select the four bottom end nodes of columns. Set them supported by pressing Fixed from contextual menu.
   
   
   
2. Start to add linear loads by selecting Linear load from ribbon tab.
   
   
   

3. Define the load by first selecting the end node of a top chord and then the other end node of the beam.

   
   
   
   
4. Add linear loads to the other top chords of the frame in the same way as previous. In this example the values of linear loads are set to 8 kN/m in the negative Z direction of 3d model.
   
   
   
5. The analysis model is now ready for solving.
   
   
   

Solve the study

1. Select Solve from ribbon tab.
   
   
   
2. The stress plots of study members can be now examined. The results display can be selected as colored or diagram. The displacements of structure can be visualized by dragging Displacements slider. The support reactions of supported nodes are shown when Show support forces and Show support moments are selected.