Docking cone Model characteristics and limitations: The model will give a contact force when a point (representing the tip of a docking pin) enters into a cylinder and comes in contact with the internal cylinder walls. It will be detected if the entry into the cylinder opening is successful or not. Until a successful entry is made, the model will give zero forces. Rotation symmetric stiffness around the longitudinal axis is assumed. The contact force acts normal to the internal surface of the cylinder (which can be conical). The transverse relative motion between the two will be limited by the radial clearing at the respective longitudinal distance, DZ, see Figure 3. Outside this limit, structural stiffness will give a restoring force directed towards the centre. Friction forces are neglected. Any contact forces in longitudinal direction may be modelled by an additional spring. Figure 3: Docking cone - Relation between radial and contact force Bumper Group Fixed Elongation Coupling