Paper Details

An Aircraft is a very complex mechanical structure having very high structural safety. Due to staticoverloading the aircrafts are seldom fail in its service life. As the continuous operation of an aircraft fatigue cracks areinitiate and propagate due to the fluctuating service loads acted in an aircraft structure. Fatigue and damag e tolerancedesign and analysis plays an important role in ensuring the airworthiness of an aircraft during its service life. This studydeals with the damage tolerance evaluation of the stiffened panel consisting of a large cutout for passenger window andbulkheads on either side of the cutout. The passenger window cutout region in the fuselage is a critical location from thefatigue crack initiation point of view. The maximum tensile stress location will be identified in the panel. The linear stati cstress analysis is carried out by using MSC NASTRAN and PATRAN Software. Fatigue is a phenomenon in which theload carrying ability of structures decreases when subjected to fluctuating loads. The fatigue reveals itself in the form ofcracks which propagate. The cracks initiated in the critical location could lead to the catastrophic failure of the aircraftif unnoticed. A crack is initiated in the maximum stress region from the analytical model of stiffened panel. The panel isanalysed for different crack length by increasing the crack length in the direction perpendicular to the loading direction.Stress intensity factor is calculated for different crack length. The ability of the bulk heads in arresting the crack on bothsides of the window cutout region is calculated analytically by comparing the stress intensity factor values with thefracture toughness of the material. The residual strength is calculated for skin and bulkhead to demonstrate thebulkheads crack arrest capability and plot the graphs.

Amaljith H, Subin P George, Girish K.E, “DAMAGE TOLERANCE EVALUATION OF A PANEL WITH WINDOW CUTOUT AND FRAMES IN THE FUSELAGE OF A TRANSPORT AIRFRAME”, International Journal of Advance Engineering and Research Development (IJAERD), Vol. 1, Issue 11, pp. 160-169, November 2014.