An improved numerical scheme of DEFEM with distributed forces on the boundary of colliding particles

Based on the concept of embedded discrete element (EDE), the force distribution on the particle boundary is obtained based on the discrete element method (DEM). The EDE is considered to cover the boundary element of the particle to deal with the distribution of particle–particle contact forces. The contact on the boundary between particles is transformed into the contact between edges. The EDE simplifies the process of the treatment of particle–particle contacts with distributed forces. According to the Hertz stress distribution, it transforms from the resultant single force calculated by the soft-sphere model in the DEM to the distributed contact forces at the boundary nodes of the particle. The EDE transforms the resultant force into the distributed boundary force and provides the boundary conditions for the finite element model. This improved numerical format can also be used in the discrete element embedded final element method. The accuracy of this method is proved by a grid independence test and experimental validation. The above force transformation also helps to analyze the stress of particles in DEM.