What is the stiffness of the connection between two entities?

The stiffness of the connection between two entities is in the first place dependent on the chosen environment in the ‘Project data’ window.

Tip: The creation of connections as such, regardless of the chosen environment, is discussed in the FAQ ‘How to create a connection between two entities (1D or 2D members)?’ (FAQ ESA1107).

  • In a Truss 2D and 3D environment all beams are fully hinged connected to each other and to the supports. It’s not possible to make the connections fixed.
  • In all other environments the connection between two entities is regarded by default as infinitely rigid.

There is nevertheless an option to adapt the stiffness of the connection, namely via the Structure menu > Model data > Hinge on beam. Such a hinge can be added to the beginning and/or end node of a beam.

For the different degrees of freedom (for displacement & rotation) can in each case be chosen between ‘Rigid’ (infinite stiffness), ‘Free’ (no stiffness) and ‘Flexible’ (stiffness value to be filled in by the user).


Steel connections

In case a steel connection has been created in a node, an option ‘Update stiffness’ is available in the Properties menu. By selecting this option, the stiffness value of the connection is calculated automatically. When the linear (or nonlinear) calculation is executed again, this stiffness value is taken into account in the analysis model for the distribution of the internal forces.

After the calculation, a hinge is automatically added to the node, so that the user can retrieve the calculated stiffness value.