Discrete element method study of parameter optimization and particle mixing behaviour in a soil mixer--颗粒学报PARTICUOLOGY

Bao, M., Lin, J., Zhang, F., & Yang, J. (2023). Discrete element method study of parameter optimization and particle mixing behaviour in a soil mixer. Particuology, 81, 1-14. https://doi.org/10.1016/j.partic.2022.12.011

Discrete element method study of parameter optimization and particle mixing behaviour in a soil mixer

Ming Bao ^a, Jiming Lin ^a *, Feng Zhang ^a, Jianhong Yang ^{a b}

a College of Mechanical Engineering and Automation, Huaqiao University, Xiamen, 361021, China
b Postdoctoral Workstation, Fujian South Highway Machinery Company, Quanzhou, 362021, China

10.1016/j.partic.2022.12.011

Volume 81, October 2023, Pages 1-14

Received 5 September 2022, Revised 27 November 2022, Accepted 12 December 2022, Available online 31 December 2022, Version of Record 6 January 2023.

E-mail: linjiming@hqu.edu.cn

Highlights

• Orthogonal experiment and comprehensive scoring methods were carried out to find out the optimal parameter combination.

• Mixing rate of the material becomes slower and the “shaft hugging” becomes serious as soil cohesion increases.

• The wear and tear of the soil mixer increased with the increase of soil cohesion.

• The radial and tangential velocities of three soils showed a pattern of periodic oscillations.

Abstract

Soil mixing is an emerging research in the field of construction resource recovery. In this study, the mixing behaviour of soil particles in a mixer is numerically simulated by the discrete element method (DEM). A four-factor, three-level orthogonal experiment is designed to optimize the mixer design by selecting the fly-cutter speed, spindle speed, number of blades and fly-cutter diameter, using Lacey mixing index and power consumption as evaluation indicators. Then, the impact of soil cohesion and type on the mixing behaviour is investigated. The results show that the optimal parameter combination of this experiment is 280 rpm fly-cutter speed, 40 rpm spindle speed, 4 blades and 250 mm fly-cutter diameter. This optimal combination reaches a comparatively uniform state mix in 5.9 s with an average power consumption of 704.11 W. In addition, the wear and tear of the mixer increases as soil cohesion increases, while the mixing quality of materials declines, resulting in a “shaft hugging” phenomenon. The mixing efficiency varies greatly among different soil types, but the radial and tangential velocities have a similar law. This work can provide some guidance for the optimization design of a mixer and study of soil mixing.

Graphical abstract

Keywords

Soil mixing; Discrete element method; Orthogonal experiment; Lacey mixing index; Soil cohesion

文章导读