A laminate parametrization technique for discrete ply-angle problems with manufacturing constraints

In this paper we present a novel laminate parametrization technique for layered composite structures that can handle problems in which the ply angles are limited to a discrete set. In the proposed technique, the classical laminate stiffnesses are expressed as a linear combination of the discrete options and design-variable weights. An exact $\ell _{1}$ penalty function is employed to drive the solution toward discrete 0–1 designs. The proposed technique can be used as either an alternative or an enhancement to SIMP-type methods such as discrete material optimization (DMO). Unlike mixed-integer approaches, our laminate parametrization technique is well suited for gradient-based design optimization. The proposed laminate parametrization is demonstrated on the compliance design of laminated plates and the buckling design of a laminated stiffened panel. The results demonstrate that the approach is an effective alternative to DMO methods.