Parameters Optimization in the Planetary Concrete Mixers using Discrete Element Method

Abstract

Variations in the planetary mixer factor's gearbox rotation speed could impact the mixing efficiency. This article uses a three-level factorial design to experiment with planetary concrete mixing parameters. Nine simulations of different arm rotation speeds and orbital rotation speeds were conducted. The relation between the mixing index and the rotation speeds was predicted using the Response Surface Method (RSM) to find optimum values of various rotation speeds to maximize a mixing index output. This article chose the open-source software LIGGGHTS®-PUBLIC to simulate the material mixing process and analyze the mixing index using the Hertz-Mindlin and Johnson-Kendall-Robert (JKR) models to control the contact between concrete mixtures by the Discrete Element Method (DEM). According to the simulation results, an optimization rotation speed of arm 15 rpm and orbital 40 rpm demonstrated the best overall mixing index of 0.81. The simulation results of the discrete element method can provide a reference for actual product design.