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PurposeAs particulate systems evolve, sliding, rolling and collision contacts all produce forces that discrete element method (DEM) methods aim to predict. Verification of friction rarely takes high priority in validation studies even though friction plays a very important role in applications and in mathematical models for numerical simulation. The purpose of this paper is to address sliding friction in finite element method (FEM)/DEM and rolling friction in DEM.Design/methodology/approachAnalytical solutions for “block sliding” were used to verify the authors' tangential contact force implementation of 2D FEM/DEM. Inspired by the kinetic art work Liquid Reflections by Liliane Lijn, which consists of free balls responding within a rotating shallow dish, DEM was used to simulate rolling, sliding and state‐of‐rest of spherical particles relative to horizontal and inclined, concave and flat spinning platforms. Various material properties, initial and boundary conditions are set which produce different trajectory regimes.FindingsSimulation output is found to be in excellent agreement when compared with experimental results and analytical solutions.Originality/valueThe more widespread use of analytically solvable benchmark tests for DEM and FEM/DEM codes is recommended.

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A porous shape memory polymer (SMP) product is currently deployed in oil and gas wells as a sand control system. This thermally and chemically activated polymer is emerging as a smart material due to its ability to recover to a predetermined shape following environmental manipulation, even after large wash out beyond gauge hole. The SMP is molded in a cylindrical geometry with desired inner and outer diameters for oil and gas production wells. This innovative technology has proven to be a reliable sand control media, a required step in combating sand production, protecting equipment and increasing the well lifetime [1, 2]. Material properties must be known in order to define the behavior of a SMP for evaluating its application in field application. The purpose of this paper is to establish a workflow in determining the material properties necessary to describe the behavior of SMP and study SMP integrity and performance under field conditions deployed in a wellbore during hydrocarbon production. For this purpose, a finite element model coupled with dynamic fluid lab data has been designed to estimate the material properties. Hyperelastic and viscoelastic constitutive models best describe the behavior of the SMP materials. The non-linear and non-elastic behaviors of the material makes the analytical solution approach inefficient, so a finite element modeling approach has been employed to overcome this difficulty. Several lab tests at different temperature conditions have been performed to expand the knowledge on material behavior. Results in this paper suggest the designed techniques and workflow are suitable in predicting material properties of SMP under any temperature conditions. Finally, a separate finite element analysis is formulated for assessment of geomechanical loads and deformations on the SMP. A 2D fully coupled poro-elastic finite element model including geomechanical load, depletion, and drawdown effects is utilized to quantify load, strain, and permeability changes of the SMP system during production and depletion. Impact of geomechanical load during production that may reduce the permeability of the SMP and affect production was evaluated for an offshore wellbore.