Abstract
A stiffened composite panel is usually adopted for a structural component of an aircraft to avoid buckling. It is well known that stacking sequence optimizations are indispensable for the laminated composite structures. For the stiffened composite panel, they usually have more than two stacking sequences because they consist of a panel skin laminate and stiffener laminates. This causes that a couple of stacking sequences should be optimized together in the structural optimization of the stiffened composite panel. Authors have proposed a new stacking sequence optimization method called fractal branch and bound method for optimizing a single laminate. In the present study, the fractal branch and bound method is extended to optimize the multiple stacking sequences. The extended method is applied to obtain two optimal stacking sequences for a maximization of buckling load of a hat-stiffened composite panel. The improved method successfully provides two optimal stacking sequences determinately in a short time.
