Before revision: For a simply-supported shaft that is divided into n segments, the first natural frequency for a given beam, in rad/s, can be approximated as: where g is the acceleration of gravity, and the are the weights of each segment, and the are the static deflections (under gravitational loading only) of the center of each segment.
After revision: For a shaft that is divided into n segments, the first natural frequency for a given beam, in rad/s, can be approximated as: where g is the acceleration of gravity, and the are the weights of each segment, and the are the static deflections (under gravitational loading only) of the center of each segment.