EFFECTS OF SHEAR DEFORMATION AND ROTARY INERTIA ON THE FREE-VIBRATIONOF A ROTATING ANNULAR PLATE

This Tech Brief addresses the effects of shear deformation and rotary inertia on the free vibration of a rotating annular plate. Several stu dies have been done to understand these effects (Irie et at, 1982; Sin ha 1987). In particular, the importance of these terms is well known f or disks with a thickness ratio h/a > 0.05 where h is the thickness of the disk and a is its outer radius. However, there is a need to show how they affect the disk vibration as the thickness ratio increases. I t is well accepted that shear deformation and rotary inertia should be included in the analysis when h/a > 0.05 (Batoz and Dhatt, 1990). How ever, this Tech Brief will show that this criterion is not valid for a ll the modes. It will present the evolution of the number of modes cor rectly evaluated versus the thickness ratio, and, finally, will give a heuristic criterion to predict when it is necessary to consider shear deformation and rotary inertia.