| Author: | Wang, Ziyi |
| Title: | Study of size effect in mechanical behavior of granular materials through DEM investigation |
| Advisors: | Yin, Zhen-yu (CEE) |
| Degree: | M.Sc. |
| Year: | 2020 |
| Subject: | Granular materials -- Mathematical models Particles -- Mathematical models Discrete geometry Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Civil and Environmental Engineering |
| Pages: | 109 pages : color illustrations |
| Language: | English |
| Abstract: | In this master's thesis, the size effect in mechanical behavior of granular materials is studied through DEM investigation. Firstly, three methods to generate single particle loaded diametrically between at platens in order to study the size effect are compared. Simulation results are presented for the breakage force and tensile strengths analyzed using Weibull statistics of particles of different diameter sizes, and the size-hardening law was obtained. Then, DEM simulations of biaxial shear tests with different size are carried out on the uncrushable specimens with a constant confining pressures. The effects of size on the mechanical behavior of principal stress ratio, dilation strain response, the shear band thickness, particle rotational distribution have been analysed. Besides, the comparison between rigid and flexible boundary is conducted on the shear strength, dilation response curve and local void ratio. Based on the uncrushable condition, we use the replacement method to simulate the particle crushing through DEM investigation, then the comparison between shear strength, dilation response, shear failure mode and internal structure of granular assemblies among dense, medium-dense, loose specimens under crushable and uncrushable conditions undergoing plane strain shearing conditions are thoroughly investigated through a variety of micromechanical analyses and mechanism demonstrations. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 5369.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 9.59 MB | Adobe PDF | View/Open |
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