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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.

Tensile tests were performed on DP600 and DP780 dual-phase steels to determine the relative effects of bake-hardening on the static and dynamic material response. The quasi-static test variables were prestrain level, specimen orientation (longitudinal, transverse), and heat treatment (as-received, bake hardened). Dynamic tests were performed at rates ranging from 0.001/s to 500/s, with variables of prestrain level and heat treatment. Increases in the ultimate and yield strength for both DP600 and DP780 were mainly due to prestrain and strain rate effects. The bake-hardening effects varied with the material, amount of prestrain, and strain rate. Crush tests were also performed on DP780 tubes in the as-received and bake-hardened conditions at rates ranging from quasi-static up to 7250 mm/s. The energy absorption was similar regardless of the rate.