Stacking Sequence Optimizations of a Hat-Stiffened Panel Using Fractal Branch and Bound Method

摘要

Stiffened composite panels are often adopted for structural components of aircrafts to avoid buckling. It is well known that stacking sequence optimizations are indispensable for the laminated composite structures. For the stiffened composite panels, they usually have two sets of stacking sequences because they consist of a panel skin and a stiffener laminate. This causes that the two sets of the stacking sequences should be optimized at the same time in the structural optimizations for the stiffened composite panels. Authors have proposed a new stacking sequence optimization method. That was named fractal branch and bound method. But the method is limited to the problems that consist of a single stacking sequence. In the present study, the fractal branch and bound method is improved in order to apply this method to optimize the multiple stacking sequences. The improved 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.