VIBRATIONS IN SOLID RODS AND DISKS

Abstract

I. A method is described for producing on the screen of a cathode ray oscillograph a curve showing the oscillations occurring in a solid rod or disk as the result of impact. These curves are usually quite complex, as they represent combinations of several different modes of vibration. They may be analyzed, however, so that for any specimen the various component frequencies may be determined. This has been done for a great number of rods and disks, and the experimental frequencies so obtained have been compared with those calculated from theory. A discussion of the results is given.II. The solutions given by Love (5, p. 291) for the general equations of vibration applicable to transverse waves in cylindrical rods are examined, and it is shown that they do not apply to comparatively short rods. Other solutions of the same simple form are considered, and the conclusion is finally reached that a much more complex solution will be required to satisfy all the boundary conditions.