Fig. 16. Composite beam builder technology development. stations (the part must be kept in tension as it passes through the mill to prevent any rippling or folding in the bend area). Following a thorough evaluation of the results, we decided to work with a lower forming temperature material that also had a broader working range. The material selected was graphite/acrylic which forms at 140°C with a 30°C range. The selection process and criteria are discussed further in the following (Material Evaluation). Still recognizing the need for higher working temperature material, our intent was “to crawl before we walk and walk before we run.” Using the same machine previously used, but now modified to provide some temperature control, heating along the bend zone only and with a uniform drive (Figure 17b), encouraging results were obtained (Figure 17d). Although there was notable flange rippling and some twist, as well as skewing of the finished part, we were encouraged enough to ask corporate management for funding to design and build a composite structural component forming process development tool, since we had been tying up a piece of production machinery with our experiments (Figures 17a and b). Having received a go-ahead, the machine was designed and built (Figure 17c). Figure 17d shows the results. After having successfully formed a good graphite/acrylic cap we tried graphite/polyethersulfone once again. An acceptable product resulted (Figure 18). Fastening of Composite Beam Components As work on beam cap processing began to progress satisfactorily, development
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