NATURAL VIBRATYIONS OF A CIRCULAR PLATE HAVING A THINNED CENTRAL PORTION AND ATTACHED DISTRIBUTED MASS

The paper considers flexural vibrations of a circular plate with a central round portion of lesser thickness and attached distributed mass. The equation is used that determines the shape of axisymmetric flexural vibrations in a plate with uniform thickness. It has been found that the lower wave numbers are reduced as the thickness of the central portion in the plate de- creases and the magnitude of the attached distributed mass grows. Using three natural fre- quencies of flexural vibrations, it is possible to determine the radius, the thickness of the thinned central portion in the plate and the magnitude of the attached distributed mass.

plate, natural frequencies, flexural vibrations, thinned central fragment