A new contact model for modelling of elastic-plastic-adhesive spheres in distinct element method

Abstract

Viscosity, granular-temperature, and stress calculations for shearing assemblies of inelastic, frictional disks Journal of Rheology 30, 949 (1986) Abstract. Rigorous models of elasto-plastic contact deformation are time-consuming in numerical calculations for the Distinct Element Method and quite often unnecessary to represent actual contact deformation of common particulate systems. In this work a simple linear elastic-plastic-adhesive contact model for spherical particles is proposed, whereby the loading cycle is a linear plastic deformation and the unloading is elastic with a higher stiffness compared to the plastic deformation. The adhesive behaviour is considered once the unloading contact force reaches the pull-off force, at which point the contact deforms with negative elastic-adhesive stiffness. In order to account for increase in adhesion due to plastic deformation, the pull-off force is evaluated using negative linear plastic-adhesive stiffness. The model is applied to compression of spherical particles with elastic-plastic-adhesive contacts for which sensitivity analyses of the model parameters on work of compaction are carried out. As the ratio of elastic to plastic stiffness is increased, the plastic component of the total work increases for a given strain and the elastic component decreases. Large stiffness ratio values imply particles undergoing larger plastic work for a given strain. By increasing interface energy, the plastic work increases for a given solid fraction, however the elastic work does not change. In this case, the maximum tensile force is increased therefore the work of adhesion is increased.;

Micro-macro and rheology in sheared granular matter

“…We observe sticking of particles at low velocity, which is consistent with previous theoretical and experimental works [186,197,217]. Pasha et al [142] recently also reproduced the low velocity sticking using an extension of a similar, simpler model [109]. Above a certain small velocity, dissipation is not strong enough to dissipate all relative kinetic energy and the coefficient of restitution increases.…”

“…A mesoscopic model that compromises on the details of the contact model, but follows the flat contact detachment philosophy was recently proposed in Ref. [142].…”

A hybrid tabulation-scaling implementation of Thornton and Ning's plastic–adhesive particle contact theory

“…It would combine the computational speed of the models of Luding [9] and Pasha et al [10], with the predictive capabilities of the TN theory. However, such a model would be a less accurate approximation than the TS implementation presented here.…”

“…The combined effects of adhesion and plasticity can be calculated especially quickly by linear contact models such as those by Luding [9] and Pasha et al [10], but they lack a direct link between the contact model parameters and physical material properties. The contact model of Tomas [11] utilizes parameters which relate more directly to the material properties of the contacting bodies.…”