مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

شبیه‌سازی ایجاد و گسترش خرابی پوشش‌ها در ساختارهای شامل پوشش و بستر در اثر بار حرارتی با استفاده از روش المان گسسته

نویسندگان
1 گروه طراحی جامدات، دانشکده مهندسی مکانیک، دانشگاه گیلان، رشت
2 عضو هیات علمی/دانشگاه گیلان
چکیده
استفاده از پوشش‌ها در صنایع مختلفی، به منظور بهبود خواص سطحی مواد مورد استفاده قرار می‌گیرند. یکی از مودهای خرابی متداول در این ساختارها، جدایش پوشش از بستر از ریشه ترک‌های کانالی شکل می‌باشد. در این مقاله، روش المان‌ گسسته به منظور شبیه‌‌سازی فرآیند ایجاد و گسترش خرابی در اثر اختلاف ضرایب انبساط حرارتی بین پوشش و بستر، از ریشه یک ترک کانالی شکل، مورد استفاده قرار گرفت. رفتار پوشش و بستر به صورت ترد الاستیک، به طوری‌که سفتی بستر بیشتر از پوشش و ضریب انبساط حرارتی پوشش به مراتب بیشتر از بستر است، در نظر گرفته شد. همچنین خواص فصل مشترک به صورت میانگین هندسی از خواص بین پوشش و بستر می‌باشد. بارگذاری نیز به صورت کاهش دما به کل مجموعه اعمال شد. اثر پارامترهایی نظیر اختلاف ضرایب الاستیک بین پوشش و بستر و همچنین ضخامت پوشش مورد بررسی قرار گرفت. نتایج نشان داد که با افزایش اختلاف سفتی بین پوشش و بستر و همچنین کاهش ضخامت پوشش، اختلاف دمای مورد نیاز برای ایجاد جدایش اولیه در فصل مشترک، افزایش پیدا کرد. از دیگر نتایجی که می‌توان به آن اشاره کرد، تغییر در الگوی گسترش خرابی اولیه ایجاد شده، به ازای تغییر در اختلاف سفتی بین پوشش و بستر بود به طوری‌که، در پوشش‌هایی که سفتی به مراتب کم‌تری نسبت به بستر دارند، گسترش آسیب در داخل پوشش اتفاق افتاد اما برای پوشش‌های که اختلاف سفتی آن‌ها با بستر کم‌تر است، گسترش آسیب تنها در فصل مشترک ادامه پیدا کرد.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Damage initiation and propagation simulation of coatings in coating/substrate structures under thermal loading using discrete element method

نویسنده English

Mohammad Amin Ghasemi 1
1 Faculty of Mechanical engineering, University of Guilan, Guilan, Rasht
چکیده English

Coatings are used in various industries in order to improve the surface properties of materials. Delamination of coatings from their substrate, at the root of channel cracks, is one of the common failure modes in these structures. In this paper, discrete element method is used in order to simulate the initiation and propagation of damages, caused by the mismatch between the thermal expansion coefficients of coating and substrate. Coating and substrate are considered to be brittle elastic in which, substrate is stiffer than the coating, but the thermal expansion coefficient of coating is considered to be much greater than substrate. The interface properties are also considered to be the geometric average between the coating and substrate. Temperature reduction is applied to the whole structure as loading. The effect of elastic mismatch and coating thickness was investigated. The results showed that, by increasing the elastic mismatch and decreasing the coating thickness, the temperature reduction, need to delamination initiation at the interface, increased. Also, changing in the damage propagation pattern was happened by changing in the elastic mismatch. In coatings with high elastic mismatch, damage propagation was happened inside them but by increasing the stiffness, damage propagation happened at the interface.

کلیدواژه‌ها English

Coating
substrate structure
Discrete Element Method
delamination at the interface
damage initiation and propagation
[1] Z. C. Xia, J. W. Hutchinson, Crack patterns in thin films, Journal of the Mechanics and Physics of Solids, Vol. 48, No. 6, pp. 1107-1131, 2000.
[2] T. Ye, Z. Suo, A. Evans, Thin film cracking and the roles of substrate and interface, International Journal of Solids and Structures, Vol. 29, No. 21, pp. 2639-2648, 1992.
[3] H. Mei, Y. Pang, R. Huang, Influence of interfacial delamination on channel cracking of elastic thin films, International Journal of Fracture, Vol. 148, No. 4, pp. 331, 2008.
[4] H. Mei, S. Gowrishankar, K. M. Liechti, R. Huang, Initiation and propagation of interfacial delamination in integrated thin-film structures, in Proceeding of, IEEE, pp. 1-8.
[5] H. Chai, J. Fox, On delamination growth from channel cracks in thin-film coatings, International Journal of Solids and Structures, Vol. 49, No. 22, pp. 3142-3147, 2012.
[6] Y. Yan, F. Shang, Cohesive zone modeling of interfacial delamination in PZT thin films, International Journal of Solids and Structures, Vol. 46, No. 13, pp. 2739-2749, 2009.
[7] A. Abdul-Baqi, E. Van der Giessen, Indentation-induced interface delamination of a strong film on a ductile substrate, Thin solid films, Vol. 381, No. 1, pp. 143-154, 2001.
[8] W. Li, T. Siegmund, An analysis of the indentation test to determine the interface toughness in a weakly bonded thin film coating – substrate system, Acta Materialia, Vol. 52, No. 10, pp. 2989-2999, 2004.
[9] M. Ostoja-Starzewski, Lattice models in micromechanics, Applied Mechanics Reviews, Vol. 55, No. 1, pp. 35-60, 2002.
[10] K. M. Crosby, R. M. Bradley, Simulations of tensile fracture in thin films bonded to solid substrates, Philosophical Magazine B, Vol. 76, No. 1, pp. 91-105, 1997.
[11] W. Vellinga, M. Van den Bosch, M. Geers, Interaction between cracking, delamination and buckling in brittle elastic thin films, International Journal of Fracture, Vol. 154, No. 1-2, pp. 195-209, 2008.
[12] P. A. Cundall, O. D. L. Strack, A discrete numerical model for granular assemblies, Géotechnique, Vol. 29, No. 1, pp. 47-65, 1979.
[13] D. O. Potyondy, P. A. Cundall, A bonded-particle model for rock, International Journal of Rock Mechanics and Mining Sciences, Vol. 41, No. 8, pp. 1329-1364, 2004.
[14] N. Kusano, T. Aoyagi, J. Aizawa, H. Ueno, H. Morikawa, N. Kobayashi, Impulsive local damage analyses of concrete structure by the distinct element method, Nuclear Engineering and Design, Vol. 138, No. 1, pp. 105-110, 1992.
[15] F. K. Wittel, F. Kun, B.-H. Kröplin, H. J. Herrmann, A study of transverse ply cracking using a discrete element method, Computational Materials Science, Vol. 28, No. 3–4, pp. 608-619, 2003.
[16] F. K. Wittel, J. Schulte-Fischedick, F. Kun, B.-H. Kröplin, M. Frieß, Discrete element simulation of transverse cracking during the pyrolysis of carbon fibre reinforced plastics to carbon/carbon composites, Computational Materials Science, Vol. 28, No. 1, pp. 1-15, 2003.
[17] D. Yang, Y. Sheng, J. Ye, Y. Tan, Dynamic simulation of crack initiation and propagation in cross-ply laminates by DEM, Composites Science and Technology, Vol. 71, No. 11, pp. 1410-1418, 2011.
[18] D. Yang, J. Ye, Y. Tan, Y. Sheng, Modeling progressive delamination of laminated composites by discrete element method, Computational Materials Science, Vol. 50, No. 3, pp. 858-864, 2011.
[19] A. Khattab, M. J. Khattak, I. M. Fadhil, Micromechanical discrete element modeling of fiber reinforced polymer composites, Polymer Composites, Vol. 32, No. 10, pp. 1532-1540, 2011.
[20] M. J. Khattak, A. Khattab, Modeling tensile response of fiber‐reinforced polymer composites using discrete element method, Polymer Composites, Vol. 34, No. 6, pp. 877-886, 2013.
[21] D. André, I. Iordanoff, J.-l. Charles, J. Néauport, Discrete element method to simulate continuous material by using the cohesive beam model, Computer Methods in Applied Mechanics and Engineering, Vol. 213–216, pp. 113-125, 2012.
[22] L. Maheo, F. Dau, D. André, J. L. Charles, I. Iordanoff, A promising way to model cracks in composite using Discrete Element Method, Composites Part B: Engineering, Vol. 71, pp. 193-202, 2015.
[23] B. D. Le, F. Dau, J. L. Charles, I. Iordanoff, Modeling damages and cracks growth in composite with a 3D discrete element method, Composites Part B: Engineering, Vol. 91, pp. 615-630, 2016.
[24] D. André, B. Levraut, N. Tessier-Doyen, M. Huger, A discrete element thermo-mechanical modelling of diffuse damage induced by thermal expansion mismatch of two-phase materials, Computer Methods in Applied Mechanics and Engineering, Vol. 318, pp. 898-916, 2017.
[25] J. Rojek, Discrete element thermomechanical modelling of rock cutting with valuation of tool wear, Computational Particle Mechanics, Vol. 1, No. 1, pp. 71-84, 2014.
[26] H. Huang, B. Spencer, J. Hales, Discrete element method for simulation of early-life thermal fracturing behavior in ceramic nuclear fuel pellets, Nuclear Engineering and Design, Vol. 278, pp. 515-528, 2014.
[27] J. Rojek, E. Oñate, Multiscale analysis using a coupled discrete/finite element model, Interaction and Multiscale Mechanics, Vol. 1, No. 1, pp. 1-31, 2007.
[28] F. A. Tavarez, M. E. Plesha, Discrete element method for modelling solid and particulate materials, International Journal for Numerical Methods in Engineering, Vol. 70, No. 4, pp. 379-404, 2007.
[29] H. Kim, M. P. Wagoner, W. G. Buttlar, Simulation of fracture behavior in asphalt concrete using a heterogeneous cohesive zone discrete element model, Journal of Materials in Civil Engineering, Vol. 20, No. 8, pp. 552-563, 2008.
[30] H. Haddad, W. Leclerc, M. Guessasma, C. Pélegris, N. Ferguen, E. Bellenger, Application of DEM to predict the elastic behavior of particulate composite materials, Granular Matter, Vol. 17, No. 4, pp. 459-473, 2015.
[31] J. Beuth, Cracking of thin bonded films in residual tension, International Journal of Solids and Structures, Vol. 29, No. 13, pp. 1657-1675, 1992.