Stress Analysis of a Splice Joint of the Wing and Fatigue Life Estimation under Variable Loading

This paper studies the large stress induced part of the splice joint in the bottom wing skin of an aircraft due to tensile loading and its fatigue life estimation. The aero foils attached to each side of the fuselage produce lift force. These aero foils are called wings and joints in aero foils and fuselage are inevitable. The surface of the wing needs smooth surface to reduce drag force. Thus the smooth surface of aero foils is obtained by splice joint between skin plates. This research investigates the part of an aerofoil with splice joint in a bottom skin for stress analysis. The splice joint considered in this research is associated with several spar beams, ribs and stiffeners with skin plate covered around it. In this research the chord-wise splice joint of aerofoil skin is focused for stress analysis. The splice joint is riveted on multiple rows which experiences the action of tensile in plane load due to wing bending. The finite element analysis of the joint is carried out to find the stresses at rivet joint holes due to By-pass load, bearing load and secondary bending. The stress analysis is performed to evaluate the stresses around rivet holes. Analyses were performed by MSC PATRAN and NASTRAN software. The analysis revealed that the rivet joints region experience the maximum stress. The most stress concentrated part was identified by local finite element analysis of a splice joint. The maximum stress concentrated part was considered for fatigue life calculations by S-N curve method. The fatigue life of the joint and the crack initiation period is evaluated under a real service load values by local stress-strain approach