STRUCTURAL ANALYSIS ON WING BOX SPLICED JOINT FOR AN AIRCRAFT USING FINITE ELEMENT METHOD

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. The stress analysis of the joint was carried out to predict the stresses at rivet holes due to by-pass load and bearing load. The stresses were calculated using the finite element method with the aid of PATRAN/NASTRAN. A fatigue crack will appear at the location of high tensile stress in an airframe structure. Further these locations are invariably the sites of high stress concentration were studied. The life prediction of structural members are requires a model for fatigue damage build up. The stress life curve data for various stress ratios and local stress analysis was calculated to find the stress concentration. The response plots of the splice joint aircraft structure were estimated. The splice joint is one of the critical locations where fatigue crack starts to initiate. In this work estimation of fatigue life for crack initiation of splice joint structure were carried out at maximum stress location.