نویسندگان

دانشگاه تربیت مدرس

چکیده

 در این مقاله، مدل شبکه- دانه مجزای بتن برای در‌نظر گرفتن سنگدانه‌های غیردایروی در حالت دو‌بعدی توسعه یافته است. به این منظور از معادله انعطاف‌پذیر ابربیضی برای تولید سنگدانه‌ها استفاده شده تا امکان شبیه‌سازی طیف گسترده‌تری از نمونه‌ها در فضای دوبعدی به مدل شبکه-دانه مجزا اضافه شود. متناسب با این توسعه، رویه‌های لازم برای تولید سنگدانه‌ها، چینش آنها در فضا، تعیین ناحیه اثر هر سنگدانه، تعیین سطوح اندرکنشی و نقاط محاسباتی و محاسبه کرنش‌ها تشریح می‌شود. در پایان، اثر هندسه سنگدانه‌ها بر مقاومت فشاری و منحنی نرم‌شوندگی بزرگ ‌مقیاس بتن و همچنین الگوی ترک‌خوردگی بتن در تحلیل تک‌محوری فشاری مورد بررسی قرار گرفته است.‏

کلیدواژه‌ها

عنوان مقاله [English]

Extending Lattice Discrete Particle Model of Concrete for Non-circular Aggregates

نویسندگان [English]

  • M. Kamza
  • M. Safarnejad
  • S. Shahbeyk

چکیده [English]

In this paper, Lattice-Discrete Particle Model (LDPM) of concrete has been extended in 2-D to account for the effect of non-circular aggregates. To this end, the flexible equation of super-ellipse is employed for generating aggregates in order to add the simulation possibility of a greater spectrum of aggregate samples in 2-D to lattice-Discrete particle Model. Alongside this extention, required procedures for the generation of aggregates, their packing in space, the determination of influencing region of each particle, the definition of interacting surfaces and computational points and the definition of strains are outlined. Finally, the effects of aggregates geometry on macro-scale compressive strength and softening curve and also cracking pattern of concrete under uniaxial compression are discussed.

کلیدواژه‌ها [English]

  • Lattice-Discrete Particle Model (LDPM)
  • Concrete
  • meso-structure
  • super-ellipse
  • cracking
1. Lee, J. and Fenves, G. L., “A Plastic-Damage Concrete Model for Earthquake Analysis of Dams”, Earthquake Engineering & Structural Dynamics, Vol. 27, pp. 937-956, 1998.
2. Jefferson, A. D., “Craft–A Plastic-Damage-Contact Model for Concrete. I. Model Theory and Thermodynamic Considerations”, International Journal of Solids and Structures, Vol. 40, pp. 5973-5999, 2003.
3. Jason, L., Huerta, A., Pijaudier-Cabot, G., and Ghavamian, S., “An Elastic Plastic Damage Formulation for Concrete: Application to Elementary Tests and Comparison with an Isotropic Damage Model”, Computer Methods in Applied Mechanics and Engineering, Vol. 195, pp. 7077-7092, 2006.
4. Wu, J. Y., Li, J., and Faria, R., “An Energy Release Rate-Based Plastic-Damage Model for Concrete”, International Journal of Solids and Structures, Vol. 43, pp. 583-612, 2006.
5. Grassl, P., and Jirasek, M., “Damage-Plastic Model for Concrete Failure”, International Journal of Solids and Structures, Vol. 43, pp. 7166-7196, 2006.
6. Cervenka, J., and Papanikolaou, V. K., “Three Dimensional Combined Fracture-Plastic Material Model for Concrete”, International Journal of Plasticity, Vol. 24, pp. 2192-2220, 2008.
7. Nguyen, G. D., “A Thermodynamic Approach to Non-Local Damage Modelling of Concrete”, International Journal of Solids and Structures, Vol. 45, pp. 1918-1934, 2008.
8. Grassl, P., Xenos, D., Nystrom, N., Rempling, R., and Gylltoft, K., “CDPM2: A Damage-Plasticity Approach to Modelling the Failure of Concrete”, International Journal of Solids and Structures, Vol. 50, pp. 3805-3816, 2013.
9. Shahbeyk, S., Hosseini, M., and Yaghoobi, M., “Mesoscale Finite Element Prediction of Concrete Failure”, Computational Materials Science, Vol. 50, pp. 1973-1990, 2011.
10. Kim, S. M., Rashid, K., and Al-Rub, A., “Meso-Scale Computational Modeling of the Plastic-Damage Response of Cementitious Composites”, Cement and Concrete Research, Vol. 41, pp. 339-358, 2011.
11. Bolander, J. E., and Saito, S., “Fracture Analyses using Spring Networks with Random Geometry”, Engineering Fracture Mechanics, Vol. 61, pp. 569-591, 1998.
12. Cusatis, G., Pelessone, D., and Mencarelli, A., “Lattice Discrete Particle Model (LDPM) for Failure Behavior of Concrete. I: Theory”, Cement and Concrete Composites, Vol. 33, pp. 881-890, 2011.
13. Cusatis, G., Pelessone, D., and Mencarelli, A., “Lattice Discrete Particle Model (LDPM) for Failure Behavior of Concrete. II: Calibration and Validation”, Cement and Concrete Composites, Vol. 33, pp. 891-905, 2011.
14. Cusatis, G., Bazant, Z. P., and Cedolin, L., “Confinement-Shear Lattice Model for Concrete Damage in Tension and Compression: I. Theory”, ASCE Journal of Engineering Mechanics, Vol. 129, pp. 1439-1448, 2003.
15. Cusatis, G., Bazant, Z. P., and Cedolin, L., “Confinement-Shear Lattice Model for Concrete Damage in Tension and Compression: II. Computation and Validation”, ASCE Journal of Engineering Mechanics, Vol. 129, pp. 1449-1458, 2003.
16. Cusatis, G., Bazant, Z. P., and Cedolin, L., “Confinement-Shear Lattice CSL Model for Fracture Propagation in Concrete”, Computer Methods in Applied Mechanics and Engineering, Vol. 195, pp. 7154-7171, 2006.
17. Schauffert, E., and Cusatis, G., “Lattice Discrete Particle Model for Fiber-Reinforced Concrete. I: Theory”, ASCE Journal of Engineering Mechanics, Vol. 138, pp. 826-833, 2012.
18. Alnaggar, M., Cusatis, G., and Di Luzio, G., “Lattice Discrete Particle Modeling (LDPM) of Alkali Silica Reaction (ASR) Deterioration of Concrete Structures”, Cement and Concrete Composites, Vol. 41, pp. 45-59, 2013.
19. Smith, J., Cusatis, G., Pelessone, D., Landis, E., O'Daniel, J., and Baylot, J., “Discrete Modeling of Ultra-High-Performance Concrete with Application to Projectile Penetration”, International Journal of Impact Engineering, Vol. 65, pp. 13-32, 2014.
20. Javidan, F., Shahbeyk, S., and Safarnejad, M., “Lattice Discrete Particle Modeling of Compressive Failure in Hollow Concrete Blocks”, Computers and Concrete, Vol. 13, pp. 437-456, 2014.
21. Wang, Z. M., Kwan, A. K. H., and Chan, H. C., “Mesoscopic Study of Concrete I: Generation of Random Aggregate Structure and Finite Element Mesh”, Computers & Structures, Vol. 70, pp. 533-544, 1999.
22. Junyong, W., and Zhengyue, R., “Generation and Evaluation on Random Polyhedron Aggregate Model”, Proceeding of the 12th International Conference of International Association for Computer Methods and Advances in Geomechanics, Goa, India, 2008.
23. Caballero, A., Lopez, C. M., and Carlo, I., “3D Meso-Structural Analysis of Concrete Specimens under Uniaxial Tension”, Computer Methods in Applied Mechanics and Engineering, Vol. 195, pp. 7182-7195, 2006.
24. Hafner, S., Eckardt, S., Luther, T., and Konke, C., “Mesoscale Modeling of Concrete: Geometry and Numeric”, Computers & Structures, Vol. 84, pp. 450-461, 2006.

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