Design of laminates by a novel "double-double'' layup

We introduce the double-double composite layup method and highlight its advantages over the current industry standard layup method. Proof that the double-double (DD) layup method can significantly reduce the required number of plies in laminates and therefore reduce the weight of composite structures is provided. The 4-ply [+/-phi/+/-psi] sub-laminates can also make the design and manufacturing processes simpler and less prone to error compared to conventional (quad) layups. Layup homogenization that makes the novel layup method a viable option by mitigating warpage of non-symmetric laminates is also investigated both analytically and experimentally to prove its effectiveness.