Abstract—The attachment joints are inevitable in any large structure like an airframe. Splicing is normally used to retain a clean aerodynamic surface of the wing skin. The wings are the most important lift-producing part of the aircraft. Wings vary in design depending upon the aircraft type and its purpose. The wing box has two crucial joints, the skin splice joint and spar splice joint. Top and bottom skins of inboard and outboard portions are joined together by means of skin splicing. Front and rear spars of inboard and outboard are joined together by means of spar splicing. The skins resist much of the bending moment in the wing and the spars resist the shear force. In this study the chord-wise splicing of wing skin is considered for a detailed analysis. The splicing is considered as a multi row riveted joint under the action of tensile in plane load due to wing bending. Stress analysis of the joint is carried out to compute the stresses at rivet holes due to by-pass load and bearing load. The stresses are estimated using the finite element approach with the help of PATRAN/NASTRAN. In a structure like airframe, a fatigue crack will appear at the location of high tensile stress. Further these locations are invariably the sites of high stress concentration. Life prediction requires a model for fatigue damage accumulation, constant amplitude S-N (stress life) data for various stress ratios and local stress history at the stress concentration The response of the splice joint will be evaluated. The splice joint is one of the critical locations for fatigue crack to initiate. In this study prediction of fatigue life for crack initiation will be carried out at maximum stress location.

Index Terms—Splice joint, Finite element analysis, Wingbox, Fatigue, Stress analysis, Life prediction.

Cite: S Sarath, Jason Cherian Issac, and K E Girish, "Analysis of the Wingbox with Spliced Skin and Estimation of the Fatigue Life for the Wingbox," International Journal of Mechanical Engineering and Robotics Research, Vol. 2, No. 2, pp. 154-163, April 2013.