TENSILE STRAIN-RATE EFFECT IN MECHANICAL-PROPERTIES OF DUMMY HTPB PROPELLANTS

The tensile strain rate effect in tensile strength and elongation at break for a series of filled dummy hydroxy-terminated polybutadiene (HTPB) propellant binders was studied. The data were obtained at various tensile strain rates from 10(-4) to 10(-1) s-1 on two types of specimens at room temperature. The ''high velocity ductility'' behavior, which is qualitatively similar to those of unfilled elastomers, was revealed. This means that the breaking strain increases markedly at elevated strain rates. For ''Bukkon-type'' and rod-shaped specimens, test results are consistent with each other. The fact that the increased filled solids level leads to a decreased breaking elongation capability and an increased tensile strength was obviously found. (C) 1993 John Wiley & Sons, Inc.