REACTION-TIME RESPONSE OF AIRCRAFT CRASH

The safety related structures of a Nuclear Power Plant (NPP) are requi red to be designed for the impact of aircraft. The reaction-time respo nse is usually obtained assuming the target to be rigid. The assumptio n is claimed to be conservative in the case of stiff structures. The e ffect of target yielding has been studied by considering an aircraft c rash upon the outer containment of an NPP. It has been observed in thi s investigation that the assumption of a rigid target is unconservativ e for some of the cases. It is usually assumed that variation in crush ing strength has very little effect on the reaction from the target. H owever, the sensitivity analysis for reaction-time response indicates that both linear mass density and crushing strength are sensitive in a ffecting the reaction from the target, depending upon the characterist ics of the aircraft and the striking velocity. The concept of confiden ce level has been investigated in relation to inclined targets also an d confidence curves are obtained for aircraft.