No abstract

SUMMARYWe describe an efficient load-balancing algorithm for parallel simulations of particle-based discretization methods such as the discrete element method or smoothed particle hydrodynamics. Our approach is based on an orthogonal recursive bisection of the simulation domain that is the basis for recursive particle grouping and assignment of particle groups to the parallel processors. Particle grouping is carried out based on sampled discrete particle distribution functions. For interaction detection and computation, which is the core part of particle simulations, we employ a hierarchical pruning algorithm for an efficient exclusion of non-interacting particles via the detection of non-overlapping bounding boxes. Load balancing is based on a hierarchical PI-controller approach, where the differences of processor per time step waiting times serve as controller input.

No abstract

This contribution presents an enhanced discrete-element model with special focus on modelling of cohesive ductile materials. The model is based on a basic three-dimensional discrete-element model consisting of spherical rigid particles, which is used to model noncohesive granular material. This basic model is enhanced by including special interactions. These interactions allow for the description of cohesive ductile behaviour of the modelled material. It is shown that by including these interactions in the discrete-element model, the failure modes of highly ductile materials like aluminium can be qualitatively as well as quantitatively described. The validity of the model is shown by the comparison of different simulated material tests with the experimental counterpart.

No abstract