A new algorithm has been implemented in Robot that lets you calculate a structure with releases. (The DSC algorithm option is available in the Tools menu > Job preferences > Structure analysis dialog.). For any bar, for which you have defined any type of analysis, with the following releases:
- Regular
- Unilateral
- Elastic
- Elastic and unilateral
the following operations are performed:
- A new node is generated in the structure when the structure model is generated.
- The input element with the release is modified in such a way that the new node replaces the old one in the element (the old node remains in the other structure elements).
- Between the old and the new node, Robot creates the DSC element (Discontinuity). See the following image.
The DSC element is a 2-node element, where the nodal forces are generated according to the following formula:
where k = [ki]; i=1, Ndl is the stiffness vector assigned to the particular degrees of freedom.
The stiffness matrix of the element has the following structure:
where T is the matrix of transformation from the local base to the global one, inherited from the bar element, and diag(k) is the diagonal matrix created from vector k.
Using the DSC elements, now lets you define elastic releases in a bar.