Stress analysis of the spar and evaluation of shear buckling in the web region

Transport aircraft typically have two spars in their wings which carry the major bending loads coming on the wings. Sometimes an auxiliary spar is employed for the landing gear attachment. The aerodynamic lift load acting on the top and bottom surfaces of the wing gets transferred to the rib structures which in-turn gets transferred to the spar web as concentrated shear loads. These shear loads cause bending of the spars which are the major loading on the spars. In addition fuel loads inertia loads as well as engine attachment loads are also transferred to the spar. In this project the spar of a typical transport wing will be considered for a detailed investigation. A realistic static loading scenario will be assumed for which a detailed stress analysis of the spar will be carried out using FEA. In particular the susceptibility of buckling of the spar web will be studied. The web is subjected to in-plane bending as well as shearing loads. The buckling behavior of the webs under this combined loading condition will be analyzed. Both SOM and FEA methods will be employed in this study.