As composite manufacturing processes evolve and composite structures becomeever more complex the role of geometry and built-in geometric features increase therole of ply movement during mold closure and compaction. With a greater amountof constraints and ply movement, the friction that develops between the prepreg pliesand the tooling surfaces and/or between one ply to another become a significant forcewhich is a factor in formation of defects such as ply wrinkles. As such a greater understandingof ply friction and its implementation into process modeling is justified.In this work Hexcel IM7/8552 8HS, is characterized for ply friction using a customcharacterization rig. The rig compresses a layer of prepreg onto a tooling surface witha prescribed pressure and heats the prepreg layer in accordance to an autoclave heatingcycle while pulling the tooling surface out in a testing frame capable of measuringthe required force to do so.Current simulation tools for modeling the autoclave process in order to predictoutcomes such as a structures spring-in due to manufacturing utilize only simplemodels for this frictional behavior. This work uses an approach with currently availabletools to implement experimentally determined ply friction data for modeling themanufacturing process using user subroutines. Results of simulation predicts thatcompression along the fiber direction during the compaction stage of the autoclavecycle is concentrated in the radius region which is experimentally shown to cause plywrinkling. In conclusion this work will present various aspects of ply friction characterization,coupon level experimentation with curved beam samples, and processmodeling.
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