Abstract—Fuselage is a primary structural component used for accommodating passengers in transport aircrafts. Normally fuselage is a built-up structure with structural members along longitudinal and circumferential directions. The skin used for the structure is a thin member with orthogonal stiffening. The design of these structures is a challenging field as the designer has to come out with the minimum weight without any compromise on safety of the structure. The current paper deals with the stress analysis of the pressure bulkhead at the rear end in the fuselage structure. Fuselage experiences a small percentage of lift loads, but the dominating load on the fuselage is the Inertia load. When the aircrafts fly over high altitude an internal pressurization is applied to create the sea level atmospheric pressure inside the fuselage cabin. This internal pressurization is considered to be one of the critical load cases in the design and development of the aircraft. A rear pressure bulkhead with all stiffening members is considered in this analysis. Due to internal pressurization the rear pressure bulkhead will undergo out of plane bending. One surface of the pressure bulkhead will undergo tension and the other will undergo compression simultaneously, as a result the stiffening members attached to the rear pressure bulkhead will also undergo tension and compression modes. Because of the built up construction one of the rivet locations will have more tensile stress. The high tensile stress locations will be critical from the fatigue crack initiation point of view. If the crack in a critical location goes unnoticed it could lead to a catastrophic failure of the airframe. A Stress analysis is carried out on rear pressure bulkhead panel to identify the maximum tensile stress location. Fatigue life to crack initiation at the location of highest tensile stress will be predicted using constant amplitude S-N data for the material used.

Index Terms—Fuselage, Pressure bulkhead, Internal pressurization, Finite element method, Stress analysis, Fatigue life, Crack initiation

Cite: Sreyas Krishnan S, Anish R, and Girish K E, "Stress Analysis of a Rear Pressure Bulkhead of the Fuselage Structure and Fatigue Life Estimation," International Journal of Mechanical Engineering and Robotics Research, Vol. 2, No. 2, pp. 170-177, April 2013.