STRUCTURAL DESIGN FOR ACOUSTIC FATIGUE
Rept. for 11 June 1962-30 Sep 1963
DOUGLAS AIRCRAFT CO LONG BEACH CA
Pagination or Media Count:
Results of either descretely or randomly excited structural acoustic tests are extended through an analytical approach and these results are presented as design nomographs. The source of acoustic excitation was considered to be the propulsion system the structure of main interest was the lighter structural configuration common to wing trailing edges, empennage, or fuselage afterbody. These structural components are most commonly exposed to acoustic environments and are such that other design criteria are not critical. The design results are presented as a function of the allowable random fatigue life of the material. Use of elevated temperature data for this fatigue life would account for the direct effect on the material of elevated temperature. No attempt was made to account for the over-all effect of elevated temperature this depends so greatly on the response of the adjoining structure that it is beyond the scope of this study. Additionally, for a majority of the structural components under study the damage occurs at takeoff when temperatures are nominal and combined effects are insignificant.