Figure 5. Interaction of forming methods and flow processes. process parameters developed for one prepreg may not be applicable to another even if they have similar fiber areal weight and resin content. PRACTICAL FORMING EXPERIENCE Forming Methods Various forming processes require different combinations of the flow processes identified in section on Flow Processes. These are summarized in Figure 5 (after6). For successful part manufacture the flow processes must be managed to control or avoid: * Fiber direction re-orientation. * Consistent ply thickness. * Ply wrinkling. * Ply bridging. As shown in Figure 5 the more complex the part configuration the larger the number of flow processes required and therefore the increase in challenge of managing the forming process. w w w. s a m p e . o r g Examples of typical forming characteristics are shown in Figure 6 including common issues and an ideal state. Careful management of all processing conditions is required to achieve the ideal state on a consistent basis. In addition to the material and process parameters referenced already we must consider the tensioning and draping of the stamp forming blank over the tool. These can be evaluated with simulation software. Digital Simulation of Forming Examples below show forming simulation using Aniform™ simulation software9 to quantify regions of high tension with high compression in the same geometry as well as material choice considerations. Note in Figure 7 that using a highly drapable PEEK fabric resulted in fair results for a complex geometry with forming in compression being the wrinkle forming area of concern. In the second example in Figure 8, it is noted that use of a UD PEKK Tape to form complex M A R C H /A P R I L 2 0 2 0 | SAMPE JOURNAL | 11http://www.sampe.org