CompositesWorld
Issue link: https://cw.epubxp.com/i/632301
FEBRUARY 2016 42 CompositesWorld INSIDE MANUFACTURING Next, two choreographed robots — a six-axis arm that articu- lates the part layup tool and a four-axis pick-and-place kinematic robot that places the patches onto the tool — precisely orient the patches along calculated load paths (see "Learn More"). Tis creates highly optimized preforms for complex structures very quickly. "We have developed preforms that form the whole part or, as in this case, provide only local reinforcement," says Michl. Te dry fber patches are stabilized with a powdered binder that dissolves into the part's matrix resin during impregnation and cure. Although most often used with liquid molding processes (e.g., infusion, resin transfer molding or injection molding), Cevotec patches also can be used with wet layup or prepreg, according to Michl, with the latter typically providing enough resin to sufciently infltrate the patches. An important feature of FPP, however, is knowing where to put patches and how they should be oriented. "It can be difcult to predict strength due to complex loading and failure mecha- nisms," Michl concedes. "But we have developed an approach that produces good results, including an algorithm to optimize the overlap between patches, which is key to achieving the highest strength and stifness in the fnal structures." Cevotec's in-house software suite is the key enabler here. It ofers a virtual process chain, from product design to part produc- tion, which predicts the end-use mechanical properties. In the end, the amount of material used is minimized because it is placed FIG. 1 Three trial boards North Kiteboarding built and tested prototypes using three diferent Cevotec patch designs (black arcs behind the colored graphics) incorporated into the bottom sides (shown here) of each board, aimed at improving board control via asymmetric torsion stifness and board fex. Boards feature drilled and counter- sunk attachment points for fns at each corner. Source | North Kiteboarding