Second-Order Parabolic Equation to Model, Analyze, and Forecast Thermal-Stress Distribution in Aircraft Plate Attack Wing–Fuselage

During a flight, the steel plate attack wing–fuselage of an aircraft is subjected to cyclical thermalstresscausedbyflightaltitudevariationthatcouldcompromisethefunctionalityoftheplate. Thus, it is compulsory after a sequence of flights to evaluate the state of plate health. In this work, we propose a new dynamic model on the basis of the physical transmission of heat by conduction governedbyasecond-orderparabolicpartialdifferentialequationwithsuitableinitialandboundary conditionstoanalyzeandforecastthermalstressesintheplateofaP64OSCARBairplane. Developing thismodelintheCOMSOLMulti-Physics R environment,afinite-elementtechniquewasappliedto achieve the thermal-stress map on the plate. The achieved results, equivalent to those obtained by a campaign of infrared thermographic experiment measurements (not yet used in the aeronautical industry),highlighttheevolutionofthethermalloadofthesteelplateattackwing–fuselage,adding evidence of possible incoming fatigue phenomena to identify in advance if the steel plate must bereplaced.