Sonic boom effects on unconventional structures in air combat training areas

Abstract

Sonic booms generated by supersonic flight portions, of air combat maneuver (ACM) training for military aircraft are a source of environmental concern to the U.S. Air Force. One of the concerns relates to potential effects on unconventional structures such as historic buildings, early American structures, and avalanche-prone areas. An upgraded statistical model is outlined for the sonic boom environment based on recent measurements and prior studies. The model is applied to the prediction of the probability of damage to unconventional structures using simple shock-response concepts and the relationship between structural velocity and stress [F. V. Hunt, “Stress and strain limits on the attainable velocity in mechanical vibration,” J. Acoust. Soc. Am. 32, 1123–1128 (1960)]. Measured residual shock spectra of a range of ACM sonic booms of widely different wave shapes are shown to be closely predicted by an ideal N-wave spectra. Structural responses to sonic booms measured on two historic buildings in the White Sands Missile Range are shown to be in good agreement with theory. [This work was supported in part by the Dept. of the Air Force, Noise and Sonic Boom Impact Technology Program, code OC-AC HAD/YA-NSBIT, Wright-Patterson AFB, OH 45443-6573.]