Rotary Wing Structural Dynamics and Aeroelasticity, Second Edition

As described earlier in Chapter 3, Yntema developed a collection of charts for rapidly estimating the natural frequencies of rotating beams for two types of mass and stiffness distributions: 1) concurrent linear distributions of both mass and stiffness, and 2) constant mass and stiffness distributions, but with a concentrated tip mass. This appendix presents a reproduction of the original charts from NACA TN 3459 (see Figs. B.1 B.10). The charts are organized according to configuration (hinged and cantilever inboard constraint) and with regard to mass distribution (linear variation of properties and concentrated mass at the end of the beam).
