Question
What is the difference between elastic links with and without shear spring location?
Answer
The difference is that in the case of an Elastic Link without Shear Spring Location, the link does not have a length, and the two nodes are just linked by the 6 stiffnesses for the degree of freedom pairs. A load on one node is transitioned to the other as the same load, considering a relative displacement between the two nodes resulting from the Force/Stiffness relationship.
In the case of a Link with Shear Spring Location, this link has a length and engages the full stiffness matrix where shear force at one end causes shear and moment at the other. There is a coupling of components in the stiffness matrix where one DOF affects more than one force component between the two nodes.
To illustrate the above, we can look at a simple example, where we have a base case of a simple cantilevering column, modelled with beam elements, and then two cases, where one of the elements of the column is replaced with an Elastic Link; one without Shear Spring Location and one with:
