Contact development between the surfaces of two tapes is considered as a critical step in processing carbon fiber reinforced thermoplastic composites. In this study, the development of intimate contact between carbon fiber reinforced Polyamide-6 (PA-6) tapes is investigated experimentally using consolidation experiments and X-ray computed tomography for quantitative contact characterization. The experimental results indicate that the development of intimate contact occurs in the range of seconds even when temperatures are only slightly above the melting temperature and applied pressures is in the range of 1-4 kPa. Experimental data are compared with the results of the two analytical models proposed by Lee and Springer as well as Yang and Pitchumani. Both models overestimate the time needed to reach full contact for the PA-6 tape. In comparison to previously investigated PEEK materials, PA-6 has a relatively low viscosity and the tapes possess a resin-rich layer near the surface, which seems to influence the contact development process. Besides the assumptions made for viscosity, the sensitivity to input parameters describing the surface topology strongly influence the model results and the accuracy of predictions.
The research investigated a new course of fire, called combat field fire (CFF), to determine CFF marksmanship standards, and where CFF should occur in marksmanship training. CFF is a complex scenario requiring changing magazines, reacting to a simulated malfunction and engaging targets within arrays that require multiple hits. Ten training companies (1976 Soldiers) from the Infantry OSUT and Basic Combat Training Brigades at Ft. Benning, GA participated. Six companies executed Army qualification at the end of basic rifle marksmanship (BRM) and CFF at the end of advanced rifle marksmanship (ARM). Four executed CFF in BRM and executed Army qualification in ARM. Performance data and Soldier interviews revealed the unique dynamics of CFF, differentiating it from Army qualification. Results showed that CFF should be in ARM, as Soldiers were not prepared in BRM for the additional skills and demands required by CFF. Recommended standards were developed for the Expert, Sharpshooter, Marksman, and Unqualified marksmanship categories, TPU (trained, needs practice, and not trained) categories., and Go/NoGo categories. 15. SUBJECT TERMS basic rifle marksmanship, advanced rifle marksmanship, combat field fire, measuring Soldier performance, marksmanship training, marksmanship qualification, combat fire, marksmanship standards SECURITY CLASSIFICATION OF 19.
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