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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), participated in a cooperative research effort to develop and assess the precision statistics of a Practice Guide for High Strain Rate Testing of Polymers. Development of the practice guide included collaborative research, surveys and an interlaboratory test program. This practice guide was incorporated into the draft SAE-J Standard (SAE J2749 High Strain Rate Tensile Testing of Polymers) and will be approved as a standard in 2008. SAE-J2749 addresses instrumentation and data analysis issues associated with measuring load. Information regarding strain measurement methods during high strain rate testing of polymers was obtained through the interlaboratory test program.

Crash simulation models require dynamic material property data to produce realistic predictions. The models often have to simulate multi-layered components that can contain polymers, foams, and metals. This paper describes a pilot study on the dynamic tensile properties of energy absorbing foams. The first phase consisted of the development of tensile test procedures suitable for high rate testing of foams. The second phase involved dynamic tensile tests on foams at rates up to 3.0 m/s. A half-scale ASTM D1623 Type A cylindrical tensile dog-bone was used for the dynamic tests. The pilot study showed that dynamic tests on foam were possible. The dynamic ultimate tensile strength, failure strain, and stiffness of three foams at various rates were measured. The groundwork has been laid for the development of a foam tensile test standard for the automotive industry, with the potential of generating shared databases.

The American Chemistry Council sponsored program to optimize a specimen design for use in high strain rate testing of long fiber-reinforced thermoplastics (LFRT) was experimentally validated through testing of injection molded long glass-filled polypropylene (LGFPP) and long glass filled Nylon ® (Nylon). It was demonstrated that the dynamic specimen geometry generated valid results for LFRT tensile tests in the quasi-static through 400/s regime. Optimum specimen size depended on the maximum test rates and end use of the data. The program results provide a basis to select specimen parameters to appropriately represent LFRT or similar materials for comparison or material property testing. Tests established the effects of injection technique; strain rate (nominal 0.1/s to 400/s); fiber fill content (20wt%, 30wt%, 40wt%), specimen type and width, panel thickness, distance to the fill gate, flow orientation, and material homogeneity.