In the connection analysis model, one of the bars is set as the load-bearing element, unless a baseplate has been defined. The remaining bars are connected to this element, on which the loads are applied.
Up until version 2025.d, the bars connected to the load-bearing element had no external links, allowing users to define forces in the direction of each axis and moments around each axis.
This is the default model and the one used in previous versions. The end of the bar has no external links, allowing the six forces to be defined.
- N - Vy - Vz - Mx - My - Mz
This is the default model and the one used in previous versions. The end of the bar has no external links, allowing the six forces to be defined. - N - Vy - Mz
This model defines loads in the XY plane. The end of the bar is constrained for displacement in the z-axis and rotation in the y-axis. - N - Vz - My
This model defines loads in the XZ plane. The bar end is constrained for displacement in the y-axis and rotation in the z-axis. - N - Vy - Vz
In this model, the end of the bar is constrained for rotation and no moments can be inserted.
These new models are useful for dealing with different structural situations. For example:
Case 1
The hollow section bar is hinged in the structural model and connected by a single bolt. If the unrestrained model is used, an unstable mechanism can be generated (Case 1 - A). By changing the load model to N - Vy - Vz, the local model of the connection resembles the connection conditions in the global model of the structure (Case 1 - B).
Case 2
Two angles are connected, where one acts as a load-bearing element and the other receives a tension applied at the centre of gravity of the section. If the unrestrained model is used, the eccentricity between the load and the connection of the load-bearing section generates a penalising moment (Case 2 - A). By changing the loading model to N - Vy - Vz, a more balanced stress distribution between the two sections is achieved (Case 2 - B).
Case 3
The eccentricity of the diagonal bar generates a moment that penalises the haunch. In this case, the displacement out of the plane formed by the beam and the diagonal is constrained, so the local model of the connection is more similar to the global model by selecting the N - Vz - My model (Case 3 - B).
