A hybrid approach for modeling of breakable granular materials using combined finite-discrete element method

• Published in: Granular matter Vol. 18; no. 1; p. 1
• Main Authors: Ma, Gang, Zhou, Wei, Chang, Xiao-Lin, Chen, Ming-Xiang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2016; Springer Nature B.V
• Subjects: Complex Fluids and Microfluidics; Discrete element method; Engineering Fluid Dynamics; Engineering Thermodynamics; Finite element analysis; Foundations; Geoengineering; Granular materials; Heat and Mass Transfer; Hybridization; Hydraulics; Industrial Chemistry/Chemical Engineering; Materials Science; Original Paper; Physics; Physics and Astronomy; Soft and Granular Matter; Polyhedral particle; Particle breakage; Granular materials; Energy dissipation; Combined FDEM
• ISSN: 1434-5021; 1434-7636
• DOI: 10.1007/s10035-016-0615-3

It is well known that particle breakage plays a critical role in the mechanical behavior of granular materials and has been a topic subject to intensive studies. This paper presents a three dimensional fracture model in the context of combined finite-discrete element method (FDEM) to simulate the breakage of irregular shaped granular materials, e.g., sands, gravels, and rockfills. In this method, each particle is discretized into a finite element mesh. The potential fracture paths are represented by pre-inserted non-thickness cohesive interface elements with a progressive damage model. The Mohr–Coulomb model with tension cut-off is employed as the damage initiation criterion to rupture the predominant failure mode at the particle scale. The particle breakage modeling using combined FDEM is validated by the qualitative agreement between the results of simulated single particle crushing tests and those obtained from laboratory tests and prior DEM simulations. A comprehensive numerical triaxial tests are carried out on both the unbreakable and breakable particle assemblies with varied confining pressure and particle crushability. The simulated stress–strain–dilation responses of breakable granular assembly are qualitatively in good agreement with the experimental observations. The effects of particle breakage on the compressibility, shear strength, volumetric response of the fairly dense breakable granular assembly are thoroughly investigated through a variety of mechanism demonstrations and micromechanical analysis. This paper also reports the energy input and dissipation behavior and its relation to the mechanical response.