Impact Test of a Single Particle Using a Drop Weight-Type Apparatus, Part III

The Fragment Size Distribution of the Fractured Product and Fatigue Fracture Under Impact Loading

Abstract

Single particle crushing of glass beads, under impact loading, classified into five ranges of grain size was carried out with a drop weight-type impact loading apparatus. The fragment size distributions of the fractured product and the fatigue fracture were investigated using size analysis with standard sieves. The experimental results are summarized as follows: 1) The relationship between the fracture probability (p_f) and impact energy of drop weight (E) is expressed by the following equation; P_f=1-exp{-(E/E₀)^1.5}, where E₀ is a referential impact energy; 2) The amount of increase in the specific surface area of the fractured product (ΔS_f) is proportional to 0.7 power of the impact energy of drop weight, regardless of the size of particle, mass and kind of drop weight; 3) The residual probability of particle (1-P_f) decreases exponentially with the number of the repeating impact load (N) as in the following equation; (1-P_f)=exp(-cN), where c is a function of the impact energy of the drop weight per unit mass of particle; 4) Particles easily fractured under small impact energy produce finer fragments compared with particles of high fracture strength.