Discrete Element Method, a Tool to Investigate Complex Material Behaviour in Material Forming

Abstract

Discrete Model is based on the description of the physical state (velocity, position, temperature, magnetic moment, electric potential ..) of a large number of discrete elements that form the media to be studied. It is not based on a continuous description of the media. Then, it is particularly well adapted to describe media evolution driven by discontinuous phenomena : - multi fracturation problems like abrasion process and composite machining, - description of multi fracturation followed by debris flow like wear study Recently, the use of discrete model has been widened to face problem encountered with complex rheological behavior and/or multi-physical behavior. Multi-physical problems face complex mathematical formulation because of the mixing of different families of differential equations when continuous approach is chosen. With the discrete model, each particle has a physical state and state evolution is due to local physical particle interaction: it is often much simple to write. Some attempt to study complex multi-physical problems has been recently presented: - thermal study of a contact and how dissymmetry appears in an apparently symmetrical problem, - study of Friction Stir Welding. This work outlines how discrete element model can be a useful tool in the simulation of material forming. Example is given on abrasion process and machining of composite.