>=There is a distinct difference in the strength characteristic of brittle materials between single impact and double impact or slow compression. The stress distribution in the Hertz's elastic contact between two spheres is reviewed briefly. The maximum points of the uniaxial tension and biaxial tension are calculated. The impact force and duration, and therefore the stresses due to the impact are related to the impact velocity, and are found that they are strongly influenced by the size of the particle.... >=There is a distinct difference in the strength characteristic of brittle materials between single impact and double impact or slow compression. The stress distribution in the Hertz's elastic contact between two spheres is reviewed briefly. The maximum points of the uniaxial tension and biaxial tension are calculated. The impact force and duration, and therefore the stresses due to the impact are related to the impact velocity, and are found that they are strongly influenced by the size of the particle. Combining the above consideration with the size effect of strength, general equations relating the breakage of brittle materials with the impact velocity are obtained. |