Free body diagrams can be utilized in dynamic systems with non-negligible friction at rotational pivots between linkages. When incorporating friction, it is essential to account for both torque and force, as friction acts as an additional force affecting the system's equations of motion. While using free body diagrams is valid, practitioners should be aware that this may lead to indeterminate solutions due to multiple statically balanced sets of forces and moments. The assumption of frictionless pivots is often a simplification to achieve unique results.
PREREQUISITESMechanical engineers, physics students, and anyone involved in analyzing dynamic systems with frictional forces at pivots will benefit from this discussion.
Sure, it's just another force. It is a bit tricky at a rotational pivot because there will be a torque as well as a force, but if you're comfortable working with torques around an idealized frictionless pivot you'll be able to introduce the effects of friction naturally.macardoso said:Are we allowed to use free body diagrams in dynamic systems where there is non-negligible friction in say the rotational pivot between two linkages?