The Discrete Element Method (DEM) has been used for modeling continua, like concrete or rocks. However, it requires a big calibration effort, even to capture just the linear elastic behavior of a continuum modelled via the classical force-displacement relationships at the contact interfaces between particles. In this work we propose a new way for computing the contact forces between discrete particles. The newly proposed forces take into account the surroundings of the contact, not just the contact itself. This brings in the missing terms that provide an accurate approximation to an elastic continuum, and avoids calibration of the DEM parameters for the purely linear elastic range.

We present a Lagrangian numerical technique for the analysis of flows incorporating physical particles of different sizes. The numerical approach is based on the particle finite element method (PFEM) which blends concepts from particle-based techniques and the FEM. The basis of the Lagrangian formulation for particulate flows and the procedure for modelling the motion of small and large particles that are submerged in the fluid are described in detail. The numerical technique for analysis of this type of multiscale particulate flows using a stabilized mixed velocity-pressure formulation and the PFEM is also presented. Examples of application of the PFEM to several particulate flows problems are given.

We present a procedure for coupling the finite element method (FEM) and the discrete element method (DEM) for analysis of the motion of particles in non-Newtonian fluids. Particles are assumed to be spherical and immersed in the fluid mesh. A new method for computing the drag force on the particles in a non-Newtonian fluid is presented. A drag force correction for non-spherical particles is proposed. The FEM-DEM coupling procedure is explained for Eulerian and Lagrangian flows and the basic expressions of the discretized solution algorithm are given. The usefulness of the FEM-DEM technique is demonstrated in its application to the transport of drill cuttings in wellbores.

This work investigates the failure patterns of ice cakes and oe-ice when loaded by a moving and sloping structure (ice-breaking ships and cones).In the paper we introduce the most frequently encountered ice-infested scenarios, the main characteristics of ice-breaking ships and the predicted failure modes of oe-ice depending on the loading conditions, the structure type and the ice feature dimensions and thickness. For the simulations, a local bonded Discrete Element Method (DEM) is used to model sea ice and its fractures. The packing of bonded spherical particles which reproduce the ice continuum can break due to ship-ice interactions and the failure modes are studied. A set of validation simulations are rst carried out. A level ice sheet breaking against an installed ice-breaking cone with dierent slope angles is studied and the results are compared with other DEM simulations. Then, a group of bonded DEM simulations are performed to predict the dierent failure modes produced when an ice-breaking ship bow contacts with ice cakes and oe-ice of dierent dimensions and thickness, typical in broken ice elds. Finally, the study of breaking a continuous level ice sheet is carried out by modeling with the bonded DEM an innite large domain of sea ice and loaded by a Single Degree of Freedom model of an ice-breaking ship.

In this chapter we present recent advances in the Discrete Element Method (DEM) and in the coupling of the DEM with the Finite Element Method (FEM) for solving a variety of problems in non linear solid mechanics involving damage, plasticity and multifracture situations.

We present a numerical procedure for elastic and non linear analysis (including fracture situations) of solid materials and structures using the Discrete Element Method (DEM). It can be applied to strongly cohesive frictional materials such as concrete and rocks. The method consists on defining non-local constitutive equations at the contact interfaces between discrete particles using the information provided by the stress tensor over the neighbour particles. The method can be used with different yield surfaces and in the paper it is applied to the analysis of fracture of concrete samples. Good comparison with experimental results is obtained.

This paper provides an immersed boundary method using a flexible local grid refinement technique for solving conjugate-heat-transfer problems. The proposed method is used to solve the flow past a heated hollow cylinder inside a channel together with the temperature field within the cylinder and then to predict turbomachinery blade cooling.

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