Optimization of postbuckled stiffened panels with multiple stiffener sizes
conference contributionposted on 28.07.2011, 12:12 by Andrew Watson, Carol A. Featherston, David Kennedy
The panel analysis and optimization code VICONOPT, based on exact strip theory, is utilized to investigate the optimum design of stiffened panels with multiple stiffener sizes or substiffeners. The optimization ensures that the buckling stability of the panel includes an allowance for postbuckling reserve of strength. The adoption of this approach necessarily results in the local buckling stress being lower than the overall buckling stress and with the introduction of substiffeners introduces extra buckling modes. This complicates the post buckling behavior of the panel which is investigated by examining the case when the smaller stiffeners lose stiffness, i.e. there is a change from a local to a torsional mode. The panels are loaded in axial compression with a sinusoidal imperfection. It is found that small mass savings are achieved by using stiffeners of more than one size and there is an increase in the spacing of the major stiffeners and transverse supports. The optimum panel designs obtained by VICONOPT are evaluated by comparison with the optimum designs produced with one size of stiffener.
- Aeronautical, Automotive, Chemical and Materials Engineering
- Aeronautical and Automotive Engineering