A simple example is presented to demonstrate the behavior of the MbDFEM cylindrical joint. The assembly consists of an L-shaped pendulum allowed to oscillate on a supporting bar, under the influence of the Earth's gravitational acceleration. Both ends of the bar are fixed to the ground. The bar and the pendulum are connected through a cylindrical joint. Unlike the hinge joint, the cylindrical joint does not restrict translation along its axis; consequently, the joint exhibits only lateral force, while the axial force is null. A protrusion is added to the pendulum, displacing its center of mass away from the mid-plane of the joint and thereby generating joint torque. An ideal cylindrical joint with no energy dissipation is modeled, so the joint axial torque is also null. To induce the sliding motion of the pendulum, the bar is inclined by one degree with respect to the global X-axis (it is not "horizontal").
The two videos below depict the assembly under investigation. The left video depicts the joint force and torque in the reference frame of the pendulum (the action), while the right video shows the force and torque in the reference frame of the bar (the reaction). As in the previous examples, d'Alembert force, d'Alembert torque and weight vectors are included at the center of mass of each part.