論文目次 |
TABLE OF CONTENTS
LIST OF TABLES VII
LIST OF FIGURES VIII
NOMENCLATURE XIII
1. INTRODUCTION 1
1.1 Granular Materials 1
1.2 Confined Compression Test 2
1.3 Friction Effect of Granular Materials 3
1.4 Shape of Granular Materials 4
1.5 Purpose 6
2. EXPERIMENTAL PROCEDURES 8
2.1 Particles with Various Friction Coefficients 8
2.2 Non-Spherical Particles 9
2.3 Experimental Setup 10
2.4 Experimental Procedure 11
3. RESULTS AND DISCUSSION 19
3.1 Mechanical Response of Granular Solid 19
3.2 Effect of Material Stiffness 23
3.3 Effect of Friction Coefficient 25
3.4 Effect of Particle Shape 30
3.4.1 Shape effect 30
3.4.2 Aspect ratio 35
3.4.3 Spherical and paired particles 37
4. CONCLUSION 40
REFERENCES 42
TABLES 45
FIGURES 48
LIST OF TABLES
Table 1 Material properties of as-received AISI 1012 steel sphere 45
Table 2 Friction coefficients of AISI 1012 steel spheres with different rust levels 45
Table 3 Dimensions of spherical and non-spherical ABS particles 46
Table 4 Material properties of spherical and non-spherical ABS particles 46
Table 5 Friction coefficients of spherical and non-spherical ABS particles 46
Table 6 Material properties of acrylic cylinder [32,33] 47
Table 7 Initial assembly state for various types of particles. 47
LIST OF FIGURES
Fig. 1 A confined compression test apparatus for bulk solid. [9] 48
Fig. 2 6-mm-diameter steel spheres of various rust levels: (a) W0; (b) W2; (c) W6; (d) W8; (e) W12; (f) W24; (g) W42; (h) W186; (i) W186+SW5; (j) W186+SW10; (k) W186+SW20. 49
Fig. 3 Nominal dimensions of various particle shapes: (a) spherical, = 1; (b) ellipsoidal I, = 1.5; (c) ellipsoidal II, = 2; (d) cylindrical, = 2; (e) paired, = 2. (Dimensions in mm) 50
Fig. 4 Schematic of an experimental setup of confined compression test. [31] 51
Fig. 5 Photograph of the experimental setup. [31] 52
Fig. 6 Top and side views of a 260-mm-long acrylic cylinder. [31] 53
Fig. 7 Free body diagram of the granular assembly and cylinder sectioned at a given height. 54
Fig. 8 Mechanical responses at different heights of the granular assembly during confined compression for steel spheres of rust level W0: (a) vertical force; (b) average vertical stress; (c) average horizontal stress; (d) average shear stress; (e) lateral pressure ratio; (f) bulk wall friction. 55
Fig. 9 Mechanical responses at different heights of the granular assembly during confined compression for spherical ABS particle ( = 1): (a) vertical force; (b) average vertical stress; (c) average horizontal stress; (d) average shear stress; (e) lateral pressure ratio; (f) bulk wall friction. 59
Fig. 10 Mechanical responses at different heights of the granular assembly during confined compression for ellipsoidal I ABS particle ( = 1.5): (a) vertical force; (b) average vertical stress; (c) average horizontal stress; (d) average shear stress; (e) lateral pressure ratio; (f) bulk wall friction. 63
Fig. 11 Mechanical responses at different heights of the granular assembly during confined compression for ellipsoidal II ABS particle ( = 2): (a) vertical force; (b) average vertical stress; (c) average horizontal stress; (d) average shear stress; (e) lateral pressure ratio; (f) bulk wall friction. 67
Fig. 12 Mechanical responses at different heights of the granular assembly during confined compression for cylindrical ABS particle ( = 2): (a) vertical force; (b) average vertical stress; (c) average horizontal stress; (d) average shear stress; (e) lateral pressure ratio; (f) bulk wall friction. 71
Fig. 13 Mechanical responses at different heights of the granular assembly during confined compression for paired ABS particle ( = 2): (a) vertical force; (b) average vertical stress; (c) average horizontal stress; (d) average shear stress; (e) lateral pressure ratio; (f) bulk wall friction. 75
Fig. 14 Free body diagram of a portion of granular assembly at a given height. 79
Fig. 15 Vertical force at different heights of the granular assembly during confined compression for steel spheres of rust level W0 and polystyrene spheres. (Data for the polystyrene spheres are taken from Ref. [31]) 80
Fig. 16 Average vertical stress at various heights for steel spheres of rust level W0 and polystyrene spheres: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. (Data for the polystyrene spheres are taken from Ref. [31]) 81
Fig. 17 Average horizontal stress at various heights for steel spheres of rust level W0 and polystyrene spheres: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. (Data for the polystyrene spheres are taken from Ref. [31]) 83
Fig. 18 Average shear stress at various heights for steel spheres of rust level W0 and polystyrene spheres: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. (Data for the polystyrene spheres are taken from Ref. [31]) 85
Fig. 19 Lateral pressure ratio at various heights for steel spheres of rust level W0 and polystyrene spheres: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. (Data for the polystyrene spheres are taken from Ref. [31]) 87
Fig. 20 Vertical force at various heights for steel spheres of rust level W0, W6, W42, W186+SW10, and W186+SW20: (a) top platen; (b) top strain gages; (c) middle strain gages; (d) bottom strain gages; (e) bottom platen. 89
Fig. 21 Average vertical stress at various heights for steel spheres of rust level W0, W6, W42, W186+SW10, and W186+SW20: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 92
Fig. 22 Average horizontal stress at various heights for steel spheres of rust level W0, W6, W42, W186+SW10, and W186+SW20: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 94
Fig. 23 Average shear stress at various heights for steel spheres of rust level W0, W6, W42, W186+SW10, and W186+SW20: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 96
Fig. 24 Lateral pressure ratio at various heights for steel spheres of rust level W0, W6, W42, W186+SW10, and W186+SW20: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 98
Fig. 25 Bulk wall friction at various heights for steel spheres of rust level W0, W6, W42, W186+SW10, and W186+SW20: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 100
Fig. 26 Vertical force at various heights for spherical (= 1), ellipsoidal II (= 2), and cylindrical (= 2) ABS particles: (a) top platen; (b) top strain gages; (c) middle strain gages; (d) bottom strain gages; (e) bottom platen. 102
Fig. 27 Average vertical stress at various heights for spherical (= 1), ellipsoidal II (= 2), and cylindrical (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 105
Fig. 28 Average horizontal stress at various heights for spherical (= 1), ellipsoidal II (= 2), and cylindrical (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 107
Fig. 29 Average shear stress at various heights for spherical (= 1), ellipsoidal II (= 2), and cylindrical (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 109
Fig. 30 Lateral pressure ratio at various heights for spherical (= 1), ellipsoidal II (= strain gages; (c) bottom strain gages. 111
Fig. 31 Bulk wall friction at various heights for spherical (= 1), ellipsoidal II (= 2), and cylindrical (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 113
Fig. 32 Vertical force at various heights for ellipsoidal I (= 1.5) and ellipsoidal II (= 2) ABS particles: (a) top platen; (b) top strain gages; (c) middle strain gages; (d) bottom strain gages; (e) bottom platen. 115
Fig. 33 Average vertical stress at various heights for ellipsoidal I (= 1.5) and ellipsoidal II (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 118
Fig. 34 Average horizontal stress at various heights for ellipsoidal I (= 1.5) and ellipsoidal II (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 120
Fig. 35 Average shear stress at various heights for ellipsoidal I (= 1.5) and ellipsoidal II (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 122
Fig. 36 Lateral pressure ratio at various heights for ellipsoidal I (= 1.5) and ellipsoidal II (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 124
Fig. 37 Bulk wall friction at various heights for ellipsoidal I (= 1.5) and ellipsoidal II (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 126
Fig. 38 Vertical force at various heights for spherical (= 1) and paired (= 2) ABS particles: (a) top platen; (b) top strain gages; (c) middle strain gages; (d) bottom strain gages; (e) bottom platen. 128
Fig. 39 Average vertical stress at various heights for spherical (= 1) and paired (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 131
Fig. 40 Average horizontal stress at various heights for spherical (= 1) and paired (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 133
Fig. 41 Lateral pressure ratio at various heights for spherical (= 1) and paired (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 135
Fig. 42 Average shear stress at various heights for spherical (= 1) and paired (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 137
Fig. 43 Bulk wall friction at various heights for spherical (= 1) and paired (= 2) ABS particles: (a) top strain gages; (b) middle strain gages; (c) bottom strain gages. 139 |
參考文獻 |
1. H. J. Herrmann, “Granular Matter,” Physica A, Vol. 313, pp. 188-210, 2002.
2. W. R. Ketterhagen, J. S. Curtis, C. R. Wassgren, A. Kong, P. J. Narayan, and B. C. Hancock, “Granular Segregation in Discharging Cylindrical Hoppers: A Discrete Element and Experimental Study,” Chemical Engineering Science, Vol. 62, pp. 6423-6439, 2007.
3. A. Formato, “Simplified Triaxial Apparatus to Test Agricultural Soils,” Soil and Tillage Research, Vol. 81, pp. 121-129, 2005.
4. J. Härtl, “A Study of Granular Solids in Silos with and Without an Insert,” Ph.D. Thesis, The University of Edinburgh, January, 2008.
5. A. J. Sadowski and J. M. Rotter, “Study of Buckling in Steel Silos under Eccentric Discharge Flows of Stored Solids,” Journal of Engineering Mechanics, Vol. 136, pp. 769-776, 2010.
6. F. Qin, L. H. Guo, J. P. Chen, and Z. J. Chen, “Pulverization, Expansion of La0.6Y0.4Ni4.8Mn0.2 During Hydrogen Absorption-Desorption Cycle and Their Influences in Thin-Wall Reactors,” International Journal of Hydrogen Energy, Vol. 33, pp. 709-717, 2008.
7. X. Hu, Z. Qi, F. Qin, and J. Chen, “Mechanism Analysis on Stress Accumulation in Cylindrical Vertical-Placed Metal Hydride Reactor,” Energy and Power Engineering, Vol. 3, pp. 490-498, 2011.
8. M. Okumura, K. Terui, A. Ikado, Y. Saito, M. Shoji, Y. Matsushita, H. Aoki, T. Miura, and Y. Kawakami, “Investigation of Wall Stress Development and Packing Ratio Distribution in the Metal Hydride Reactor,” International Journal of Hydrogen Energy, Vol. 37, pp. 6686-6693, 2012.
9. S. A. Masroor, L. W. Zachary, and R. A. Lohnes, “A Test Apparatus for Determining Elastic Constants of Bulk Solids,” pp. 553-558 in Proceedings of the 1987 SEM Spring Conference on Experimental Mechanics, Houston, Texas, USA, June 14-19, 1987.
10. Y. C. Chung and J. Y. Ooi, “Influence of Discrete Element Model Parameters on Bulk Behavior of a Granular Solid under Confined Compression,” Particulate Science and Technology, Vol. 26, pp. 83-96, 2008.
11. D. McGlinchey, Bulk Solids Handling: Equipment Selection and Operation, Blackwell Publishing Ltd., Oxford, UK, 2008.
12. D. L. Blair, N. W. Mueggenburg, A. H. Marshall, H. M. Jaeger, and S. R. Nagel, “Force Distributions in Three-Dimensional Granular Assemblies: Effects of Packing Order and Inter-Particle Friction,” Physical Review E, Vol. 63, 041304, 2001.
13. J. Wiącek, M. Molenda, J. Horabik, and J. Y. Ooi, “Influence of Grain Shape and Intergranular Friction on Material Behavior in Uniaxial Compression: Experimental and DEM Modeling,” Powder Technology, Vol. 217, pp. 435-442, 2012.
14. P. A. Cundall and O. D. L. Strack, “A Discrete Numerical Model for Granular Assemblies,” Geotechnique, Vol. 29, pp. 47-65, 1979.
15. S. E. Naeini and J. K. Spelt, “Two-Dimensional Discrete Element Modeling of a Spherical Steel Media in a Vibrating Bed,” Powder Technology, Vol. 195, pp. 83-90, 2009.
16. H. Tao, B. Jin, W. Q. Zhong, X. F. Wang, B. Ren, Y. Zhang, and R. Xiao, “Discrete Element Method Modeling of Non-Spherical Granular Flow in Rectangular Hopper,” Chemical Engineering and Processing: Process Intensification, Vol. 49, pp. 151-158, 2010.
17. Md. M. Sazzad and Md. S. Islam, “Macro and Micro Mechanical Responses of Granular Material under Varying Interparticle Friction,” Journal of Civil Engineering, Vol. 36, pp. 87-96, 2008.
18. Z. X. Yang, J. Yang, and L. Z. Wang, “On the Influence of Inter-Particle Friction and Dilatancy in Granular Materials: A Numerical Analysis,” Granular Matter, Vol. 14, pp. 433-447, 2012.
19. J. Härtl and J. Y. Ooi, “Numerical Investigation of Particle Shape and Particle Friction on Limiting Bulk Friction in Direct Shear Tests and Comparison with Experiments,” Powder Technology, Vol. 212, pp. 231-239, 2011.
20. J. Schwedes, “Review on Testers for Measuring Flow Properties of Bulk Solids,” Granular Matter, Vol. 5, pp. 1-43, 2003.
21. A. Dziugys and B. Peters, “An Approach to Simulate the Motion of Spherical and Non-Spherical Fuel Particles in Combustion Chambers,” Granular Matter, Vol. 3, pp. 231-265, 2001.
22. J. S. Yoon, A. Zang, and O. Stephansson, “Simulating Fracture and Friction of Aue Granite under Confined Asymmetric Compressive Test Using Clumped Particle Model,” International Journal of Rock Mechanics and Mining Sciences, Vol. 49, pp. 68-83, 2012.
23. M. C. Kulkarni and O. O. Ochoa, “Mechanics of Light Weight Proppants: A Discrete Approach,” Composites Science and Technology, Vol. 72, pp. 879-885, 2012.
24. A. A. Peña, R. G. Rojo, and H. J. Herrmann, “Influence of Particle Shape on Sheared Dense Granular Media,” Granular Matter, Vol. 9, pp. 279-291, 2007.
25. G. Dondi, A. Simone, V. Vignali, and G. Manganelli, “Numerical and Experimental Study of Granular Mixes for Asphalts,” Powder Technology, Vol. 232, pp. 31-40, 2012.
26. K. Szarf, G. Combe, and P. Villard, “Polygons vs. Clumps of Discs: A Numerical Study of the Influence of Grain Shape on the Mechanical Behavior of Granular Materials,” Powder Technology, Vol. 208, pp. 279-288, 2011.
27. S. J. Lee, Y. M. A. Hashash, and E. G. Nezami, “Simulation of Triaxial Compression Ttests with Polyhedral Discrete Elements,” Computers and Geotechnics, Vol. 43, pp. 92-100, 2012.
28. MatWeb, AISI 1012 steel, http://www.matweb.com/, accessed on April 16, 2013.
29. MatWeb, Chi Mei Polylac® PA-707 ABS, http://www.matweb.com/, accessed on April 25, 2013.
30. Engineers Edge, Common Plastic Molding Design Material Specification, http://www.engineersedge.com/, accessed on April 25, 2013.
31. P.-H. Chou, “Mechanical Response of Granular Solid under Confined Compression,” M.S. Thesis, National Central University, August, 2012
32. eFunda, Inc., PMMA, http://www.efunda.com/materials/polymers/, accessed on May 10, 2012.
33. W. T. Nakayama, D. R. Hall, D. E. Grenoble, and J. L. Katz, “Elastic Properties of Dental Resin Restorative Materials,” Journal of Dental Research, Vol. 53, pp. 1121-1126, 1974.
34. H. A. Janssen, “On the Pressure of Grain in Silos,” Proceedings of the Institution of Civil Engineers, Vol. 124, pp. 553-555, 1896.
35. Y. C. Chung, private communication, 2013. |