High strain rate characterisation of a glass/epoxy composite

High strain rate characterization of polymer composite materials has been l imited due to difficulties in the measuring equipment. In particular, jigs and fixtures can be subject to inertial disturbances present at speeds up t o and above 2 m/s. These disturbances are due to the phenomena of mechanica l resonance and control problems that the test equipment acquires at high s peeds. The amplitudes of the resulting oscillations increase with test spee d and change the test sample response, making results difficult to analyze. These inertial problems may be avoided if the extrapolation of low to high strain data is applicable. Tests were performed measuring material properties at increasing rates of s train. These properties included the Young's modulus, tensile and shear str engths, and the shear modulus of a glass-epoxy composite. The results show that the effect of the logarithm of the rate of strain on the material prop erties can be regarded as linear and extrapolated to provide the data at hi gh strain rates.