Ratchet coupling The ratchet coupling can take tension or compressive force. The force will start to act after a specified time. The force consists of 3 components, a constant force, a stiffness force and a damping force. The constant force component (which can be set to zero) acts from t=0. For a ratchet with compressive force, the damping will only act when the distance is decreasing and for a tension ratchet the damping will only act when the distance is increasing. It is possible to specify an event of ratchet failure. It will then fail if a specified force is exceeded. When the element fails, the tension is set to zero.