Modeling the Behavior of Dry Sand with DEM for Improved Impact Prediction

Pumpkin ball impact test is similar to simple pendulum impact test. It represents a rough handling test conducted on user interface parts to check its robusteness in case of abuse loading. The objective of this work is to create a standard simulation model that would capture the behavior of sand particles inside a rubber ball and scope is limited to create and validate a finite element model used to replicate a pumpkin ball impact test. Pumpkin ball is a rubber ball filled with dry sand up to 3/4th of its volume. The major challenge in this activity was simulating the real behavior of dry sand inside the rubber ball during the impact. Dry sand granules interact with each other as well as with the inner surface of ball during the course of impact. To capture this behaviour of dry sand granules discrete element method (DEM) was used. In the current study, the experimental test was conducted on concrete wall and measured acceleration was used for the validation of developed finite element model. The simulation results had shown a close agreement with the experimental results. The validated model is useful to verify the various design concepts early in the product development process.. Keywords: DEM, Console, User interface, Pumpkin ball, accelerometer, dry sand, finite element methods.