A new effective smeared stiffener method for global buckling analysis of grid stiffened composite panels

• Published in: Composite structures Vol. 158; pp. 83 - 91
• Main Authors: Xu, Yuanming, Tong, Yan, Liu, Manqing, Suman, Bajracharya
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.12.2016
• Subjects: Buckling; Diagonal stiffener; Global buckling load; Grid stiffened; Grid-stiffened composite panels; Loads (forces); Networks; Panels; Smeared stiffener theory; Stiffeners; Stiffness; Unit cell; Grid-stiffened composite panels; Diagonal stiffener; Smeared stiffener theory; Global buckling load
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2016.09.015

A new effective smeared stiffener method is developed to compute the global buckling load of grid stiffened composite panels. This method gives appropriate consideration of the skin-stiffener interactions based on a proposed improved mechanical hypothesis. The stiffness contribution of the stiffeners is evaluated through the force and moment effect analysis of the stiffener network on a general unit cell, and resultant stiffness matrix is applicable to different types of grid network on such unit cell by introducing a stiffener configuration parameter vector. The equivalent global stiffness matrix is then formulated by superimposing the stiffness contribution of the stiffeners and attached skin. Combined with Rayleigh-Ritz method, a general eigenfunction was derived for computing global buckling load, which fully considered the effect of the coupling stiffness and can solve the global buckling loads for a grid stiffened panel under combined in-plane forces. Finally, various test examples with different grid patterns were analyzed and results were compared with results obtained by finite element methods and those obtained with existing smeared methods. It is shown that the developed approach has better accuracy and can give highly computational efficiency for the global buckling analysis of gird stiffened composite structures.