As shown below, please use 8 fenders to restrict the motions except heave in the Hydrodynamic Response analysis. The fenders' stiffness should be large enough, for example, about 100 * omega(heave)**2 * m, where omega(heave) is the natural frequency (in rad/s) of heave, m is the mass of the structure. The frequency independent damping for heave can also be defined to model the damping of the damper. These fenders will have no effect on the RAOs obtained by the Hydrodynamic Diffraction analysis. But you can run the Hydrodynamic Response -> Freuqncy Statistic analysis to have the RAOs including these fenders's effect.
You are navigating away from the AIS Discovery experience