A novel DEM approach for modeling brittle elastic media based on distinct lattice spring model

Abstract

The Discrete Element Method (DEM), also known as Distinct Element Method (DEM), is extensively used to study divided media such as granular materials. When brittle failure occurs in continuum such as concrete or ceramics, the considered media can be viewed as divided. In such cases, DEM offers an interesting way to study and simulate complex fracture phenomena such as crack branching, crack extension, crack deviation under coupled mode or crack lip closure with friction. The fundamental difficulty with DEM is the inability of the method to deal directly with the constitutive equations of continuum mechanics. DEM uses forcedisplacement interaction laws between particles instead of stress-strain relationships. Generally, this difficulty is bypassed by using inverse methods, also known as calibration processes, able to translate macroscopic stress-strain relationships into local force-displacement interaction laws compatible within DEM frameworks. However, this calibration process may be fastidious and really hard to manage. The presented work proposes to improve the Distinct Lattice Spring Model in order to deal with non-regular domains, by using Voronoi cells, which allows to completely fill the volume space of discrete domains. With this approach, the rotational effects must be included in the contact formulation, which enables the management of large rigid body rotations. This work also introduces a simple

Bonded discrete element simulations of sea ice with non-local failure: Applications to Nares Strait

“…Future work may incorporate an optimization routine to learn the appropriate model parameters from the mismatch between model output and satellite observations. Alternatively, the use of non-local distinct lattice spring (André et al, 2019), or peridynamic models (Davis et al, 2021) could avoid the need for time intensive calibration studies, and facilitate using real-world values for the model parameters.…”

“…Similar to (Dansereau et al, 2017), we use a uniform distribution between minimum (c min ) and maximum (c max ) cohesion values when initializing our DEM particles to create heterogeneity in the ice strength and resultant failure. It is well known that bonded lattice-like DEM approaches require calibration of local parameters in order to simulate realistic macroscopic or effective response and failure properties (André et al, 2019). Therefore, we created calibration simulations to determine the appropriate local failure model values σ N,t and σ N,c .…”

Expectations and limitations of Cyber-Physical Systems (CPS) for Advanced Manufacturing: A View from the Grinding Industry

“…Given the nature of the grinding wheel structure, it should be regarded as a quasi-brittle material. In recent years, various research groups have focused their efforts on developing discrete element method (DEM) solutions to characterize the fracture behavior of these types of materials [32][33][34] Furthermore, in [35,36] the authors characterize the fracture behavior of the grinding wheel using a DEM model, they propose an experimental procedure for quantifying mechanical parameters (Brazilian test applied to grinding wheels) [35], and they describe tests for characterizing the grinding wheel material [36]. Unfortunately, this approach has not been validated for the classical problem of wheel wear.…”

A variational discrete element method for the computation of Cosserat elasticity

“…Using the proposed method allows to use the usual tools of FEM applied to a DEM and thus makes its use and analysis much easier. Also, the restrictions on meshes are relaxed allowing to use simplicial meshes in lieu of Voronoi meshes which are used in [32,2] and are cumbersome to produce. Cosserat elasticity is usually computed through a P 2 -P 1 Lagrange mixed element [37].…”