Low frequency limitations of the split Hopkinson pressure bar method for identification of complex modulus

Low frequency limitations of a recently developed method for identification of complex modulus utilizing the split Hopkinson pressure bar (SHPB) technique were investigated using computer simulations. Specifically, the effects of truncation, noise and discretization were examined. It was shown that the low frequency limitation of the method generally corresponds to the inverse of the length of the time signal. Further, it was shown that all three factors have an effect on the low frequency accuracy of the method and that careful consideration of these factors is necessary to optimize the capability of the method. Finally, it was shown how averaging techniques can be implemented to reduce the undesirable effects of truncation and noise.