This multibody system represents a three-bar swing. A geometrically exact beam is connected by revolute joints to rigid bodies that are fixed in space by spherical joints. These joint connections are modeled as holonomic constraints. A point mass is attached to the midnode of the beam. Initially, a force is applied to the point mass in the longitudinal direction of the beam. After 0.25 seconds, the force vanishes and the system undergoes free vibration.