NONCONSERVATIVE STABILITY OF A FRICTION LOADED DISK

This paper investigates the vibration of an annular disk that is subje cted to rotation and in-plane frictional traction distributed over a s ector of the disk's two faces. Technical applications include noise, v ibration, and harshness in automotive and aircraft disk brakes, clutch es, transmissions, and other rotating machine components. To the degre e that the rotor-to-stator friction in such cases is directed along th e disk's deformable surface, it is treated here as a nonconservative f ollower-type load. The vibration model incorporates membrane stiffness which derives both front rotation, and from the stresses established as a result of friction The plane stress state is determined in closed form as a Fourier series, and that solution is compared,vith the comp anion, but computationally intensive, results from finite element anal ysis. For the cases of sector-shaped and full annular loading, the vib ration model predicts the critical mode, which is defined as the one t hat becomes dynamically unstable at the lowest friction level. Vibrati on modes and propagating waves that fall into opposite symmetry classe s are shown to have opposite stability characteristics in the presence of frictional loading.