Description: A free body diagram of the bellows will show the possibility of three forces -- one in each direction, three moments -- one in each plane, and the internal pressure. Any or all of these forces and moments may fluctuate due to variations in a driving force, e.g., separation of streamlines which creates slugging of flow through an elbow. Whereas the static equilibrium condition can be analyzed and stresses and strains computed, the dynamic condition cannot be approached without information on the magnitude, frequency and location of the exciting force. Having the latter, some evaluation of the stresses to be expected can be made. By combining strains (or stresses) due to the various forces and moments, the point of maximum stress can be located and the point of maximum stress fluctuation for the fatigue cycle-amplitude-range curve can be determined. Further consideration must be given to stress concentrations. With the complete analysis in mind, we must determine how some of these forces and moments effect the tests and delineate what can he expected from the tests. This report considers each force or moment by itself and studies its relationship to the tests.
Date: February 28, 1961
Creator: Lomax, C. C.
Partner: UNT Libraries Government Documents Department