The thesis deals with bending-torsion decoupling in eigen modes of monocoque laminatedrncomposite aircraft (subsonic and supersonic) wing using commercial software ANSYS.rnTheoretical background, mathematical formulation and finite element solution for a laminatedrncomposite shell structure are presented in this study. A monocoque aircraft wing is made ofrnlaminated composite with fiber angles in each ply aligned in different direction.rnVarious airfoil thickness and ply angles were considered to study the effect of bending-torsionrndecoupling. Results obtained are presented and parametric studies are made to show the effect ofrnairfoil thickness variation and ply orientation. The effect of location of shear center relative tornthe center of gravity is also studied and the results are presented.