Automated fiber placement (AFP) machines can steer the
fibers/tows to make the so-called variable stiffness (VS) composites. They
allow the designers to fully exploit the directional properties of composite
materials to tailor the internal load distribution and improve the structural
performance. VS composites have been shown to be very promising in
the design optimization of composite panels and shells for buckling and
post-buckling performance and consequently for further reducing the
mass of future aerospace structures. In this chapter, the buckling
performance improvement of VS composite cylinders with circular and
elliptical cross sections is investigated. A metamodeling based design
optimization (MBDO) method is presented to maximize the buckling
performance of VS composite cylinders compared with their constant stiffness (CS) designs. The structural improvement mechanism via
stiffness tailoring in a VS composite cylinder is also presented and
discussed. The effects of different parameters including the cylinders’
aspect ratio and size as well as the percentage of the steered plies in the
laminate are also investigated.
Keywords: Automated fiber placement, Buckling, Composite cylinder,
Fiber steering, Optimization, Variable stiffness.
