Elasto-plastic and adhesive contact: an improved linear model and its application

An improved linear model is developed for elasto-plastic and adhesive contact. New correlations are proposed and validated to estimate the key input parameters of the model, including contact stiffness, yield point, maximum pull-off force and time step. The newly proposed contact model is applied to the analysis of single particle contact behaviour upon impact and bulk particle flow behaviour by DEM simulations. The results show that both single particle and bulk powder behave more cohesively if contact plastic deformation is taken into consideration. A cohesion yield number is proposed to describe and govern the extent of yielding when cohesive particles are in contact with each other. There is critical particle size, below which the effect of plastic deformation must be considered. This provides a new framework and criteria for elasto-plastic and adhesive contact model, and a step towards understanding the effect of plastic deformation on the behaviour of cohesive particles.