Approximate postbuckling analysis of omega-stringer-stiffened composite panels

A new approximate computational model for the postbuckling analysis is introduced to contribute to the preliminary design of thin-walled composite structures. The investigated structure is an omega stringer stiffened composite panel which is a type of stiffened panel used in current aircraft designs but is also relevant generally for application in aerospace structures and marine vessels. The model is derived by energy methods and aims to approximate the postbuckling behavior near the bifurcation point, i.e. with low load proportionality factors. The loadcase of uniaxial compression is considered and the quality of the new method is assessed in comparison to numerical methods. The overall aim is to reduce computational effort without unfeasible compromises in the quality of the results