questionable, and the lower values thereafter are of limited utility. It should be possible to draw realistic average curves from Shot 9 ac- celeration data adequate for data correlation purposes. ". ae ‘ C008. os ee4 . oft . « response limits the valuc of the data. The high amplitude fluctuations mike determination of an average value for the early portion rather * a ? o%e out in less than 0.4 sec. Whereas a complete time-history of nose, tail, and center of gravity accelerations were obtained on King Shot, the low feeds a . For instance, a smooth curve very similar to an overpressure time curve for a blast wave can be drawn through the Shot 9 center of gravity acceleration data. 6.6 SUMMARY SHOT+KNOTHCLE definitely estaolished that the most critical component of the B-36 aircraft for a tail-on exposure was not the wing. Based on = most critical component if the aircraft is flying directly toward or away from the burst point. However, the loads measured on IVY and UP} so we Prior to IVY, the measured structural responses of test aircraft and the theoretical analysis indicated that normaily the wing is the the initial allowable tail load (38,200 1b), the horizontal tail was the most critical; however, using the new allowable load (63,000 lb), there is considerable doubt as to which component, aft fuselage or horizontal tail, is the most critical, From the loads measur. on these two operations, the most critical component cannot be definitely determined. The horizontal tail loads were approximetely 50 rer cent of design limit, and the loads measured on the fuselage were aporoximateiy 4O per cent of design limit. However, the fuselage loacs were measured at a station which may not be critical. cefore the most critical component can ve determined, the data presented in this report must be used to rerform a complete analysis of the aft fuselage section response, These <-ta then should be verified by in- flight measurements at the critical stations. In zeneral the theoreti- cally predicted loaus for the wing sectior of the o+36D aircraft were in asreement with the measured ioads. ? wee Mel te : The predicted loads for the aft fuselare ana tail section, nowever, were Low for IVY and high for UPSHOTHVGTHCLE, There has ceen a dynamic analysis conducted on the wing s :ction of the 5-360 aircraft but rot on the aft fuselage or tail section. zecause 7ust induced ioads cause acceleration and vitration of the elas- «ic airrlane structure, the metnod of dynamic analysis must be employed for analyti> determination of structural Loads. Therefore, a complete dyrnamit analysis is reauired for accurate srediction of aircraft loads encountered in the vitinity cf 4 nuclear explosion. In Fig. 6.4 the normal certer of gravity acceleration and the wing root cending moment are fresente: fur comparison. It can ce clearly seen from tnis fiyure thet tre «ing vending moment and normal acceleration are of tne sare frequency ani relative magnitude. Theoretical analysis nes snown this is an ecre-‘tec ‘orrelation. The Loads measured frem tne -rcund-reflected shock wave on the horizontal stabilizer and aft ciseace were hiner than those from the direct shock wave, This fact can ce seen very clearly in the Shot 9 response data rresented in unarter 5. It aiso can ce seen fror these time-nisturies thot tne vicration from tne direct shock wave had not 97 = ee , - , , “4 - i Sed aate eee PR ts rd Yesieea ee 2 9s @ e eo @ 9 e =} pee: ee co: _% a 6 ‘