نوع مقاله : مقاله پژوهشی

نویسنده

دانشیار، دانشکده مهندسی مکانیک، پژوهشگاه هوافضا، وزارت علوم، تحقیقات و فناوری، تهران، ایران

چکیده

مدل میکرومکانیکی برای تحلیل شکست مواد مرکب تقویت‌شده با الیاف تک‌جهته در بارگذاری عرضی ارائه می‌شود که علاوه بر مدل‌سازی رفتار غیرخطی زمینه در اثر بارگذاری بیش از حد تسلیم آن، قابلیت مدل‌سازی عیوب ناشی از جدایش بین زمینه و الیاف و ترک‌های زمینه را دارد. میکروساختار مواد مرکب با استفاده از سلول‌های واحد و با فرض متناوب بودن میکروساختار توصیف می‌شود که در آن الیاف به‌صورت منظم یا غیرمنظم توزیع شده است. مدل میکرومکانیک برای تعیین استحکام عرضی مواد مرکب با زمینه‌ی آلومینیوم و الیاف کربن استفاده می‌شود که الیاف با توجه به صلبیت بالای آن‌ها با مدل الاستیک خطی همسانگرد و زمینه با مدل الاستیک-پلاستیک همسانگرد توصیف می‌شود. معیار پیدایش عیوب در زمینه براساس معیار حداکثر کرنش اصلی و با توجه به میزان کرنش نهایی ماده‌ی زمینه توصیف می‌شود که افزایش تنش اعمالی پس از پیدایش عیب منجر به کاهش سفتی ماده و در نهایت ایجاد ترک در ماده‌ی زمینه می‌شود. اتصال بین زمینه با استفاده از مدل چسبناکی توصیف و پیدایش عیوب در آن با توجه به میزان استحکام محوری و برشی اتصال تعیین می‌شود. مدل میکرومکانیک برای مطالعه‌ی اثر توزیع هندسی الیاف در میکروساختار، درصد حجمی الیاف، اثر استحکام اتصال بین زمینه و الیاف استفاده شده و نواحی ایجاد عیوب و نحوه‌ی گسترش آن‌ها، علاوه بر نمودارهای تنش-کرنش در ماده مرکب تعیین می‌شود.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Micromechanical fracture modeling of unidirectional composite material under transverse loading

نویسنده [English]

  • Mohammad Tahaye Abadi

Aerospace Research Institute, Ministry of Science, Research and Technology, Tehran, Iran

چکیده [English]

A micromechanical model is presented to analyze the fracture response of unidirectional composite materials considering the nonlinear behavior of matrix material under loading more than the yield strength as well as the fiber-matrix debonding and matrix cracking. The composite microstructure is characterized with repeating unit cell with regular or random fiber-packing patterns. The micromechanical model is employed for composite material with aluminum matrix and carbon fibers. The high rigidity fibers are modeled as linear isotropic elastic material, while matrix material is characterized with elastic-plastic model. The damage initiation stage in matrix material is described by principal strain criterion accompanied with damage evolution considering stiffness degradation up to crack formation. The bonding between fiber and matrix is modeled using cohesive model, in which damage initiation criterion depends on the normal and shear strength of the cohesive zone. The micromechanical model is employed to study the effects of fiber distribution, fiber volume fraction, fiber-matrix bonding strength on the crack propagation through the microstructure as well as the stress-stain graph up to the fracture of microstructures.

کلیدواژه‌ها [English]

  • Fiber-matrix debonding
  • Matrix Cracking
  • Micromechanics
  • Fracture strength
[1] Plueddemann, E. P., Silane Coupling Agents, Springer, 1982.
[2] Drzal, L. T., Rich, M. J., and Lloyd, P. F., "Adhesion Of Graphite Fibers To Epoxy Matrices: I. The Role Of Fiber Surface Treatment," The Journal of Adhesion,  Vol.  16, No.  1, pp. 1-30, 1983.
[3] Ghosh, S., Ling, Y., Majumdar, B., and Kim, R., "Interfacial Debonding Analysis In Multiple Fiber Reinforced Composites," Mechanics of Materials,  Vol.  32, No.  10, pp. 561-591, 2000.
[4] Hobbiebrunken, T., Hojo, M., Adachi, T., De Jong, C., and Fiedler, B., "Evaluation Of Interfacial Strength In Cf/Epoxies Using Fem And In-Situ Experiments," Composites Part A: Applied Science and Manufacturing,  Vol.  37, No.  12, pp. 2248-2256, 2006.
[5] Gamstedt, E., and Sjögren, B., "Micromechanisms In Tension-Compression Fatigue Of Composite Laminates Containing Transverse Plies," Composites Science and Technology,  Vol.  59, No.  2, pp. 167-178, 1999.
[6] Martyniuk, K., Sørensen, B. F., Modregger, P., and Lauridsen, E. M., "3d In Situ Observations Of Glass Fibre/Matrix Interfacial Debonding," Composites Part A: Applied Science and Manufacturing,  Vol.  55, No.  , pp. 63-73, 2013.
[7] Hojo, M., Mizuno, M., Hobbiebrunken, T., Adachi, T., Tanaka, M., and Ha, S. K., "Effect Of Fiber Array Irregularities On Microscopic Interfacial Normal Stress States Of Transversely Loaded Ud-Cfrp From Viewpoint Of Failure Initiation," Composites Science and Technology,  Vol.  69, No.  11, pp. 1726-1734, 2009.
[8] Li, J., Liu, X., Yao, X., and Yuan, Y., "A Micromechanical Debonding Analysis Of Fiber-Reinforced Composites Due To Curing Residual Stress," Journal of Reinforced Plastics and Composites,  p. 0731684415584952, 2015.
[9] Vaughan, T., and McCarthy, C., "Micromechanical Modelling Of The Transverse Damage Behaviour In Fibre Reinforced Composites," Composites Science and Technology,  Vol.  71, No.  3, pp. 388-396, 2011.
[10] González, C., and LLorca, J., "Mechanical Behavior Of Unidirectional Fiber-Reinforced Polymers Under Transverse Compression: Microscopic Mechanisms And Modeling," Composites Science and Technology,  Vol.  67, No.  13, pp. 2795-2806, 2007.
[11] Piggott, M., "Why Interface Testing By Single-Fibre Methods Can Be Misleading," Composites Science and Technology,  Vol.  57, No.  8, pp. 965-974, 1997.
[12] Pindera, M.-J., Khatam, H., Drago, A. S., and Bansal, Y., "Micromechanics Of Spatially Uniform Heterogeneous Media: A Critical Review And Emerging Approaches," Composites Part B: Engineering,  40, 5, pp. 349-378, 2009.
[13] Smit, R., Brekelmans, W., and Meijer, H., "Prediction Of The Mechanical Behavior Of Nonlinear Heterogeneous Systems By Multi-Level Finite Element Modeling," Computer Methods in Applied Mechanics and Engineering, Vol. 155, No. 1, pp. 181-192, 1998.
[14] Dijkstra, K., and Gaymans, R., "Nylon-6 Rubber Blends. 2. Temperature Effects During High-Speed Deformation," Journal of materials science, Vol.  29, No. 12, pp. 3231-3238, 1994.
[15] Buryachenko, V., Micromechanics Of Heterogeneous Materials, Springer, 2007.
[16] Suquet, P., "Elements Of Homogenization For Inelastic Solid Mechanics," Homogenization techniques for composite media, Vol.  272, pp. 193-278, 1987.
[17] Tahaye Abadi, M., "Characterization Of Heterogeneous Materials Under Shear Loading At Finite Strain," Composite Structures, Vol.  92, No. 2, pp. 578-584, 2010.
[18] Hyer, M. W., Stress Analysis Of Fiber-Reinforced Composite Materials, DEStech Publications, Inc, 2009.
[19] Callister, W. D., and Rethwisch, D. G., Fundamentals Of Materials Science And Engineering, Wiley, 2013.
[20] Camanho, P. P., and Dávila, C. G., "Mixed-Mode Decohesion Finite Elements For The Simulation Of Delamination In Composite Materials," NASA Report, 2002.
[21] Thomson, R. D., and Hancock, J., "Ductile Failure By Void Nucleation, Growth And Coalescence," International Journal of Fracture,  Vol.  26, No.  2, pp. 99-112, 1984.
[22] Agarwal, H., Gokhale, A., Graham, S., and Horstemeyer, M., "Void Growth In 6061-Aluminum Alloy Under Triaxial Stress State," Materials Science and Engineering: A,  Vol.  341, No.  1, pp. 35-42, 2003.
[23] Abadi, M. T., "Micromechanical Modeling Of Heterogeneous Materials At Finite Strain," Wiley Encyclopedia of Composites, 2011.
[24] Wang, J.-S., "Random Sequential Adsorption, Series Expansion And Monte Carlo Simulation," Physica A: Statistical Mechanics and its Applications,  Vol.  254, No.  1, pp. 179-184, 1998.