Stability Analysis And Design Of Aircraft Composite Wing Panel

Advanced composite materials have been widely used in aerospace,marine engineering and other military and civilian fields.One of the typical structures used in aircraft composite wing is stiffened panel.Once stiffened panels buckled,it may cause disastrous consequences,so it is necessary to conduct the study of the stability of the stiffened panel.In fact,buckled stiffened plate still has the great load-carrying capacity which is the post-buckling strength of the stiffened panel.Therefore,it is necessary to study the post-buckling behavior of the structure to improve the load-Carrying capacity of the structure.Due to design requirements or design constraints,the stringer of the panels are often terminated at the locations near the wing ribs or fuselage frames,near the front and rear beams of the wings,near the wings and fuselage openings or near the fuel tanks of the wings.Load transfer pathes of the stiffened panel abruptly changes because of the stringer discontinuities,resulting in the stress concentration at the run-out.The run-out of the stringer and the discontinuities are one of the key concerns for the structural detail design of the composite stiffened panel.In this paper,finite element models of stiffened panels under axial compression are established.The results of the finite element model are in good agreement with the experimental data and the results of the engineering analysis,which proves the correctness of the model simplification method.In order to obtain the empirical results quickly,the program is compiled according to the engineering method.In this paper,the post-buckling path of the stiffened panel considering the factors of geometric nonlinearity is obtained by using the implicit nonlinear module of finite element software.Then the parametric modeling of the stiffened panel is done and the influence of the stiffened panel strength with different rib heights,thicknesses,width,density and sections is studied.Under the compressive load,the run-out of the stringer will fail in the interface of the stiffener and skin causing by inter-laminar shear stress.In this paper the advantages and disadvantages of three kinds of run-out with different configurations are studied.it also studies the influence of the angle,the edge width,the thickness of the skin and the starting position of the thickening of the skin on the stress concentration and debonding of the stringer run-out.