The General Link element is used to model dampers, base isolators, compression-only element, tension-only element, plastic hinges, soil springs, etc. The 6 springs individually represent 1 axial deformation spring, 2 shear deformation springs, 1 torsional deformation spring and 2 bending deformation springs as per Figure 1.1. Among the 6 springs, only selective springs may be partially used, and linear and nonlinear properties can be assigned. The general link can be thus used as linear and nonlinear elements.
The General Link element can be largely classified into Element type and Force type depending on the method of applying it to analysis. The Element type general link element directly reflects the nonlinear behavior of the element by renewing the element stiffness matrix. The Force type on the other hand, does not renew the stiffness matrix, but rather reflects the nonlinearity indirectly by converting the member forces calculated based on the nonlinear properties into external forces.