3. MED: discrete numerical model of granular materials

There are several categories of discrete numerical methods (Discrete Element Method, Contact Dynamics, quasi-static approaches), differing mainly in the way they deal with inter-grain contacts and inertial terms. In this chapter, we will focus solely on the Discrete Element Method (DEM), which is undoubtedly the most popular approach today, and the simplest to implement at the cost of regularizing contact laws. This method undoubtedly has its origins in the so-called molecular dynamics methods used since the second half of the 20th century to simulate collections of interacting gas particles or molecules. The development of MED and its application to geomaterials was initiated in the early 1970s by Cundall and colleagues