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Recently the University of Dayton Research Institute (UDRI), the Society of Automotive Engineers (SAE), and the High Strain Rate Plastics Committee (HSRPC), conducted an interlaboratory test program (ITP) to assess the precision of the Practice Guide for High Strain Rate Testing of Polymers. In addition to generating precision statistics, the intent of this ITP was to develop the Practice Guide to a level of maturity where it could be released as an SAE-J Standard in 2005. The ITP was conducted at 12 laboratories using five polymers: high density polyethylene (HDPE, Dow Chemical Co.); polycarbonate/acrylonitrile-butadiene styrene terpolymer (PC/ABS, LG Chem, Ltd.); thermoplastic elastomer-olefinic (TPO, Solvay Engineered Polymers); long glass (11 mm) fiber 40% filled polypropylene (GF PP, LNP Engineering Plastics); and short glass (2-3mm) fiber 30% filled polyamide 66 (GF PA, Bayer Polymers LLC) and two nominal plastic strain rates, 40/s and 400/s.

Numerical simulations indicate that blast loading on aircraft structural joints can impart loading rates in excess of 10 Mlb/sec (ten million pounds per second, Reference 1). Experimental evidence, on the other hand, suggests that mechanical joint failure loads are highly loading rate dependent; for example, the failure load for a dynamically loaded tension joint can double from its static value. This paper discusses the progress and to-date findings of research on the assessment of strength failure of aircraft structural joints subjected to loading rates expected from an internal explosive detonation, and several associated experimental procedures to generate such dynamic loading. This work is conducted at MDC and at the University of Dayton Research Institute (UDRI) in support of the FAA Aircraft Hardening Program.