STRESS ANALYSIS AND FATIGUE LIFE PREDICTION OF WING- FUSELAGE LUG JOINT ATTACHMENT BRACKET OF A TRANSPORT AIRCRAFT

Abstract

Civil transport aircraft is used for ferrying passengers from one place to another. Aircraft is a highly complex flying structure. Generally transport aircraft undergoes nominal maneuring flights. During the flight when the maximum lift is generated, the wings of the aircraft will undergo highest bending moment. The bending moment will be maximum at the root of the wing which caused highest stress at this location. Wings are attached to the fuselage structure through wing-fuselage attachment brackets. The bending moment and shear loads from the wing are transferred to the fuselage through the attachment joints. In this project bending load transfer joint is considered for the analysis. First one needs to ensure the static load carrying capability of the wing-fuselage attachment bracket. Stress analysis will be carried out for the given geometry of the wing-fuselage attachment bracket. Finite element method is used for the stress analysis. In the current project, an attempt will be made to predict the fatigue life of wing-fuselage attachment bracket in a transport airframe. In a metallic structure fatigue manifests itself in the form of a crack which propagates. Fatigue cracks will appear at the location of high tensile stress locations. These locations are invariably of high stress concentration. Fatigue life calculation will be carried out for typical service loading condition using constant amplitude S-N data for various stress ratios and local stress history at stress concentration. In this paper for modeling CATIA V5 software is used and for analysis tool MSC/ PATRAN and MSC/ NASTRAN 2010.