نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکترا، دانشکده مهندسی مکانیک، دانشگاه بوعلی سینا، همدان، ایران

2 استاد، دانشکده مهندسی مکانیک ، دانشگاه بوعلی سینا همدان، همدان، ایران

3 استاد، دانشکده مهندسی مواد دانشگاه صنعتی شریف، تهران، ایران

چکیده

در مقاله حاضر، اثر درصد نانو‌ذرات خاک رس و کربنات کلسیم بر میکروسختی نانوکامپوزیت‌های پلی‌پروپیلن با انجام آزمون ویکرز مورد بررسی قرار گرفته است. برای مقایسه با نتایج تجربی، یک مدل سه بعدی اجزای محدود آزمون ویکرز نیز در کد آباکوس شبیه‌سازی شده است. به‌منظور پیش‌بینی تغییر شکل پلاستیک کامپوزیت پلیمری، از معیار تسلیم دراگر-پراگر استفاده شده است. ضرایب دراگر-پراگر با انجام آزمون‌های کشش و فشار به‌صورت مجزا تعیین شده و در مدل عددی وارد شده است. دو فرض جریان پتانسیل وابسته و غیر وابسته در شبیه‌سازی در نظر گرفته شده است و زاویه اتساع مناسب با حداقل کردن خطای تجربی و عددی محاسبه شده است. در ادامه مدل‌های تحلیلی ماکرومکانیکی و میکرومکانیکی به‌منظور پیش‌بینی تاثیر نانوذرات بر سختی پلی‌پروپیلن بررسی شده است. هرچند نتایج نشان می‌دهند که مدل‌های تحلیلی قانون مخلوط‌ها و مارش دقت مناسبی دارند (حدود 10 درصد خطا)، اما می‌توان با انتخاب زاویه اتساع مناسب در روش عددی، به جواب‌های بسیار خوبی رسید (کمتر از 2 درصد). علاوه بر آن مشاهدات تجربی نشان می‌دهند، افزودن خاک رس و کربنات کلسیم باعث افزایش مدول الاستیسیته، تنش تسلیم کششی و فشاری و همچنین میکروسختی پلی‌پروپیلن می‌شود.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Experimental, analytical and numerical investigation of polypropylene nanocomposites microhardness

نویسندگان [English]

  • javad payandehpeyman 1
  • Gholamhossein majzoobi 2
  • Reza Bagheri 3

1 Department of Mechanical Engineering, Bu-Ali Sina University, Hamedan, Iran

2 Department of Mechanical Engineering, Bu-Ali Sina University, Hamedan, Iran

3 Department of Material Engineering, Sharif University of Technology, Tehran, Iran

چکیده [English]

In the present paper, the effects of nanoclay and nano calcium carbonate on polypropylene nanocomposites microhardness are assessed using Vickers test. Also, a 3D finite element model of Vickers test has been simulated by Abaqus code to compare to the experimental results. The Drucker-Prager yield criterion has been used to predict the polymeric composite plastic deformation. The Drucker-Prager parameters implemented in the numerical model are determined by a tension and a compression test separately. Two associative and non-associative plastic flow assumptions are considered and an appropriate dilation angle is derived by minimizing the error difference of experimental and the numerical results. Furthermore, micromechanical and macromechanical models are investigated to predict nanoparticles effect on the polypropylene microhardness.  Although the results show that analytical models including Marsh and rule of mixture models have suitable accuracy (about 10% error), excellent results (less than 2% error) can be obtained by selecting appropriate dilation angle value in the numerical method. Moreover, experimental evidences show that adding nanoclay and nano calcium carbonate increases elastic modulus, tensile and compressive yield stress as well as microhardness of the polypropylene

کلیدواژه‌ها [English]

  • Vickers microhardness
  • Drucker-Prager Criterion
  • Micromechanic Model
  • Macromechnic Model
  • Polypropylene Nanocomposites
[1]    Golgoon, A. Aliofkhazraei, M. Toorani, M. Moradi, M. H. and Golgoon, E., “The Structure and Corrosion Properties of Polyester-Clay Nanocomposite Coatings and Effect of Curing on Coatings Properties”, In Persian, Journal of Science and Technology of Composites, inpress.
[2]    Mohammad aliha, M. Moosavi, A. Mehri Khansari, N. and Safarabadi, M., “Effects of Alumina and Hydroxyapatite Nanoparticles on Fracture Toughness of PMMA Based Dental Composite”, In Persian, Journal of Science and Technology of Composites, Vol. 2, No. 2, pp. 9-16, 2015.
[3]  Mohsenzadeh, R. and Shelesh-Nezhad, K., “Experimental Studies on the  Durability of PA6-PP-CaCO3 Nanocomposite Gears”, In Persian, Journal of Science and Technology of Composites, Inpress.
 [4]   Payandehpeyman, J. Majzoobi, G. and Bagheri, R., “Determination of the Extended Drucker-Prager Parameters Using the Surrogate-Based Optimization Method for Polypropylene Nanocomposites”, J. Strain Anal. Eng. Des., Inpress.
[5]    Afshar, A. Massoumi, I. Khosh, R. L. and Bagheri, R., “Fracture Behavior Dependence on Load-Bearing Capacity of Filler in Nano- and Microcomposites of Polypropylene Containing Calcium Carbonate”, Mater. Des., Vol. 31, No. 2, pp. 802–807, 2010.
 [6]   Suwanprateeb, J., “Rapid Examination of Annealing Conditions for HDPE Using Indentation Microhardness Test”, Polym. Test., Vol. 23, No. 2, pp. 157–161, 2004.
[7]    Goyal, R. K. Tiwari, A. N. and Negi, Y. S., “Microhardness of PEEK / Ceramic Micro- and Nanocomposites : Correlation with Halpin–Tsai model”, Mater. Sci. Eng. A, Vol. 491, No. 1–2, pp. 230–236, 2008.
[8]    Minkova, L. and Filippi, S., “Characterization of HDPE-g-MA/Clay Nanocomposites Prepared by Different Preparation Procedures: Effect of the Filler Dimension on Crystallization, Microhardness and Flammability”, Polym. Test., Vol. 30, No. 1, pp. 1–7, 2011.
[9]    Tabor, D., The Hardness of Metal. Oxford University Press, 1951.
[10]  Balta-Calleja, F. J. and Fakirov, S., Microhardness of Polymers. Cambridge University Press, 2000.
[11]  Flores, a. Ania, F. and Balta-Calleja, F. J., “From the Glassy State to Ordered Polymer Structures: A Microhardness Study”, Polymer (Guildf)., Vol. 50, No. 3, pp. 729–746, 2009.
[12]  Suwanprateeb, J., “Calcium Carbonate Filled Polyethylene : Correlation of Hardness and Yield Stress”, Compos. Part B Eng.,Vol. 31, pp. 353–359, 2000.
[13]  Jumahat, A. Soutis, C. Jones, F. R. and Hodzic, A., “Compressive Behaviour of Nanoclay Modified Aerospace Grade Epoxy Polyme,”, Plast. Rubber Compos., Vol. 41, No. 6, pp. 225–232, 2012.
[14]  Rikards, R. Flores, A. Ania, F. and Kushnevski, R., “Numerical-Experimental Method for the Identification of Plastic Properties of Polymers from Microhardness Tests”, Computational Materials Science. Vol. 0256, No. 4, 1998.
[15]  Payandehpeyman, J. Majzoobi, G. and Bagheri, R., “Deriving Parameters of Pressure-Dependent Yield Surface for Polymeric Composites Using Kriging-Based Optimization Method”, In Persian ,Modares Mech. Eng., , Vol. 16, No. 1, pp. 280-290, 2016.
[16]  Seltzer, R. Cisilino, A. P. Frontini, P. M. and Mai, Y.-W., “Determination of the Drucker–Prager Parameters of Polymers Exhibiting Pressure-Sensitive Plastic Behaviour by Depth-Sensing Indentation”, Int. J. Mech. Sci., Vol. 53, No. 6, pp. 471–478, 2011.
[17]  Lu, Y. B. and Li, Q. M., “Dynamic Behavior of Polymers at High Strain-Rates Based on Split Hopkinson Pressure Bar Tests”, Int. J. Impact Eng., Vol. 38, No. 1, pp. 41–50, 2011.
[18]  “https://en.wikipedia.org/wiki/Vickers_hardness_test.” .
[19]  Batra, R. C. Gopinath, G. and Zheng, J. Q., “Material Parameters for Pressure-Dependent Yielding of Unidirectional Fiber-Reinforced Polymeric Composites”, Compos. Part B Eng., Vol. 43, No. 6, pp. 2594–2604, 2012.
[20]  Rittel, D. and Dorogoy, a., “A Methodology to Assess the Rate and Pressure Sensitivity of Polymers Over a Wide Range of Strain Rates”, J. Mech. Phys. Solids, Vol. 56, No. 11, pp. 3191–3205, 2008.
[21]  Mata, M. Casals, O. and Alcala, J., “The Plastic Zone Size in Indentation Experiments: The Analogy with the Expansion of a Spherical Cavity”, Int. J. Solids Struct., Vol. 43, No. 20, pp. 5994–6013, 2006.
[22]  Dodiuk, H. and Goodman, S., “Handbook of Thermoset Plastics,” Third ed, William Andrew, New York, pp. 623, 2013.
[23]  Lubin, G., “Handbook of Composites,”Van Nostrand Reinhold Company, New York, pp. 417, 1982.
[24]  http://www.hubermaterials.com.
[25]  Selvakumar, V. Palanikumar, K. and Palanivelu, K., “Studies on Mechanical Characterization of Polypropylene / Na + -MMT Nanocomposites”, J. Miner. Mater. Charact. Eng., Vol. 9, No. 8, pp. 671–681, 2010.
[26]  Bilotti, E. Zhang, R. Deng, H. Quero, F. Fischer, H. R. and Peijs, T., “Sepiolite Needle-Like Clay for PA6 Nanocomposites: An Alternative to Layered Silicates?”, Composites Science and Technology., Vol. 69, No. 1, pp. 15-16, 2009.
[27]  Pahlavanpour, M. Moussaddy, H. Ghossein, Hubert, E.P. and Levesque, M., “Prediction of Elastic Properties in Polymer–clay Nanocomposites: Analytical Homogenization Methods and 3D Finite Element Modeling” ,Computational Materials Science., Vol. 79, No. 1, pp. 206-215, 2013.
[28]  Bhandari, N. L. Lach, R. Grellmann, W. and Adhikari, R., “Depth-Dependent Indentation Microhardness Studies of Different Polymer Nanocomposites”, Macromol. Symp., Vol. 315, No. 1, pp. 44–51, 2012.
[29]  Tweedie, C. a. and Van Vliet, K. J., “On the Indentation Recovery and Fleeting Hardness of Polymers”, J. Mater. Res., Vol. 21, No. 12, pp. 3029–3036, 2006.