Modeling the robotic manipulation of woven carbon fiber prepreg plies onto double curved molds: a path dependent problem

This paper investigates the behavior of woven prepreg plies being placed on a weakly double curved mold by a robot. It is essential that the draped configuration is free from wrinkles. The baseline is a virtual draping environment that can plan and simulate robot draping sequences. It consists of a kinematic mapping algorithm for obtaining target points for the grippers on the mold surface. A simple motion planner is used to calculate the trajectories of the grippers. Here, two conceptually different draping strategies are employed. Finally, the two generated draping sequences are simulated using a transient, non-linear finite element model and compared w.r.t. their predicted wrinkle formations. Material data are obtained by means of tension, bias-extension and cantilever tests. The numerical examples show that the virtual draping environment can aid in developing the automatic draping system but that the generation of feasible draping sequences is highly path dependent and non-trivial.