COMPARISON OF APPROACHES FOR SONIC FATIGUE PREVENTION

Exploratory development on sound-induced fatigue of flight vehicle structures has brought about numerous and varied approaches for the prevention of sonic fatigue. They range from purely theo9etical techniques for designing the structures to full scale proof testing of a flight vehicle. A generalized approach to prevention of sonic fatigue is presented which enumerates the necessary steps needed for the required prediction of fatigue life. Five approaches are summarized where two approaches are primarily concerned with designing the initial structure with a satisfactory fatigue life. The other three approaches are to determine the fatigue life of structural designs by experimental tests prearranged to be representative of the true environments. The structural designs are modified and improved to meet the necessary fatigue life requirements, thus preventing sonic fatigue during their expected normal service life. These approaches are compared on the basis of their assumptions for true environment representation, verification and complexity of analytical and experimental procedures and results. (Author) Presented at the ASD 1963 Science and Engineering Symposium, 18-19 Sep 1963, at Wright-Patterson Air Force Base, Ohio.