Dear Colleagues,

Stationary or quasi-static granular mechanics have been a part of the traditional soil mechanics for centuries. In contrast, moving granular materials has not received comparable scientific attention until much later. An intense growth of research in the dynamics of granular materials has been observed in the past several decades. The field has now become truly multi-disciplinary, including all engineering disciplines and physics, with recent interactions with chemical, biological, and human sciences. Due to the dissipative nature of grain interactions, the dynamics of granular materials display many surprising characteristics. Flowing granular materials act like a fluid. However, without external excitation, this fluid “freezes” to become a solid. The transition between phases, unlike ordinary materials, eludes a description based on currently available thermodynamic. Likewise, moving granular materials display rich mixing/de-mixing that has no observed analogues in ordinary fluids. The above phenomena are known for the simplest granular flows where the grains only exert contact forces to each other. When compounded with long range, such as electrostatic and magnetic, forces, the richness and complexity of phenomena drastically increase. The field of dynamic granular materials may provide a platform for a dialog amongst all researchers in studying discrete systems with complex interactions.

Prof. Dr. Hayley H. Shen
Guest Editor

• granular
• dynamics
• micromechanics
• discrete systems