Local buckling of blade stiffened variable angle tow panels

In recent years analytical methods and finite element analysis (FEA) have shown that variable angle tow (VAT) laminates deliver a significant improvement in buckling and post- buckling performance. However to date, most research has been limited to simple geome- tries, such as plates and shells, with standard boundary conditions; a large gap exists between these analyses and real life structural scenarios. A potential for exploitation of this enhanced buckling performance exists by applying VAT to the skin of a stiffened panel configuration. Herein, a generalised Rayleigh-Ritz procedure is used to perform prebuckling and buckling analysis on a stiffened VAT panel taking into account the often neglected, yet significant, stiffener foot and transverse shear effects via a first order shear deformation theory (FSDT). Initial results, compared with FEA (ABAQUS), indicate that this semi- analytical method is an accurate and efficient alternative to the computationally expensive FEA and hence, is useful for the design and optimisation of stiffened VAT panels.