Geotechnical Spring This component is used to specify geotechnical springs in the global X-Y plane suitable for modelling cyclic geotechnical data with degradation. The stiffness of the spring is degraded based on the secant stiffness to ultimate resultant displacement from initial position. The spring properties are given as force/displacement pairs, displacement must be increasing. Non-linear damping properties may be applied as pairs of displacement and damping coefficients. The damping force is applied using the following model: \[ F = C (d)\cdot|\dot{d}|^{P}\cdot sign(\dot{d})\] Allowing the user to add arbitrary non-linear damping as a function of displacement. See the RIFLEX manual for additional details.