The kinetics of powder settlement caused by low level vibration and elastic stresses

Based on general principles of metastable states and the mechanics of continuous media, the kinetic equation of settlement of granular material subjected to low level vibration and elastic stresses is developed. Because of confining pressure, the material remained nearly as a solid block and never assumed loose free moving behavior. In such conditions, a rather classical approach using classical elasticity with reference to the microstructural nature of granular media was sufficient to capture some of its properties. The proposed model used the energy barrier criteria for evaluation of densification of granular materials in isotropic and anisotropic loading conditions. The model predicts settlement dependence on vibration amplitude and number of cycles for given range of confining pressure and deviatoric stresses. The prediction matches well with the experimental data.