Abstract
A new evaluation technique has been developed to measure the hardness of particulate matter by using a compression and stress relaxation test. In this paper we determined the constant k' in Hertz equation from the analysis of the proportional region and compared it with k' calculated from Young's modulus and Poisson's ratio for the verification of this method. Furthermore the effect of particle size distribution on the experimental results was discussed. It was shown that the constant k' obtained from the analysis of the proportional region was well correlated with the calculated k'. It was also found that the value of k' was almost independent of the particle size distribution. These results indicate that the constant k' determined by this method can be a new hardness index of particulate matter.
