Tow Path Planning Strategies for Fiber Steered Laminates

Fiber steering leads to gaps and overlaps in plies and laminates. The position of these gaps and overlaps as well as their total volume/area is very much influenced by the seeding strategy when transforming from a theoretical to a manufacturing design. The theoretical designs obtained from a steered fiber laminate optimization routine are the starting point of a tow path planning step. The seed points together with the theoretical fiber angle determine the path of a tow. Normally, seed points are determined by a manufacturing engineer. In this paper, two different strategies to automate the selection of initial seed points and subsequent points based on the calculation of previous tow paths are proposed and evaluated. For two-dimensional plate problems both proposed methods reduce the gaps and overlaps. The method based on the median tow path is spreading gaps and overlaps more uniformly and yields fewer gaps and overlaps. A cut and restart procedure is discussed and implemented, which can be used to manually or automatically prevent/limit overlaps and fill large gaps.