The establishment of the normal contact force model for a one-dimensional sphere chain subjected to impact load

The normal contact force determines the behavior of a particle system. To investigate the normal contact force in a one-dimensional sphere chain subjected to impact load, by comparing the simulation results of the existing typical normal contact force models embedded in the discrete element program, an improved normal contact force model was proposed in this paper. The improved model consists of two parts: the Cundall model for loading and the Daniel model for unloading. Moreover, a systematic test was designed to verify the accuracy and applicability of the improved model. The results showed that the calculated contact force curves agree well with the experimental results. Furthermore, the improved model is implemented in the solution algorithm without need for complex numerical methods and parameters fitting, leading to more efficient simulations.