As far as I understand a rod that has an angular velocity is static. Nonetheless, if we analyze a particle in the rod, this particle will be subject to a centripetal force that will be proportional both to the angular force and radius. Now I understand that the external forces and momenta exerted on the rod are zero; thus, it's static. How does one take into account that the bar is suffering certain stress due to rotation? How is it calculated? Is it really static? I understand those forces are internal, but those are the forces that are studied in a class like strength of materials right? Thanks a lot for taking the time to answer my question.