Overlap-stiffened panels for optimized buckling performance under minimum steering radius constraints

Recent research on variable stiffness laminates have shown both numerically and experimentally that further improvement the buckling performance is possible by incorporating overlaps result in thickness profiles. We present concept of overlap-stiffened designs take advantage non-linear coupling between tow steering local thickness, allowing embedded regions higher into individual plies a variable-angle (VAT) laminate. The proposed method naturally copes with minimum radius constraints different manufacturing processes connecting transition means fiber arcs, such curvature always cope desired constraint. study focuses two tow-steering processes: automated placement (AFP) continuous shearing (CTS). Each ply exploring design described using 5 variables, producing straight stiffener. A first benchmark compares optimized for maximum volume-normalized under bi-axial compression against reference straight-fiber In second benchmark, panels were weight load constraint, compared For AFP CTS, verified VAT can achieve at least double an panel. Moreover, same carrying capacity optimal panel, demonstrating potential to include thickness.