نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجوی دکترا، مهندسی مکانیک، دانشگاه بیرجند، بیرجند.

2 استادیار، مهندسی مکانیک، دانشگاه بیرجند، بیرجند.

3 استادیار، مهندسی مکانیک، دانشگاه صنعتی نوشیروانی، بابل.

10.22068/jstc.2019.92109.1473

چکیده

با توجه به ترکیبات فیزیکی و خواص مکانیکی متفاوت فلزات و کامپوزیت‌ها، اتصال کارآمد آن‌ها یکی از چالش‌های مهم در صنایع مختلف به‌شمار می‌رود. شکست در اتصالات چسبی معمولاً نتیجه‌ی توزیع غیریکنواخت تنش و کرنش است که با مقادیر بیشینه نزدیک دو انتهای هم‌پوشانی مشاهده می‌شود. در این مطالعه از الیاف کربن به‌عنوان المان تقویتی در لایه چسب استفاده شده و جهت بهبود توزیع تنش از درجه‌بندی خواص در طول هم‌پوشانی به‌صورت متقارن و به‌وسیله الیاف کربن و شیشه استفاده می‌شود. همچنین با استفاده از یک روش جدید، تاثیر وجود پله معکوس در استحکام اتصال بررسی شده است. علاوه بر این، مدل‌سازی المان محدود برای بیان نحوه توزیع تنش برشی و پوسته‌کنی در لایه چسب و همچنین تحلیل دلایل افزایش استحکام اتصال در نمونه‌های پله‌دار به‌کار گرفته می‌شود. استفاده از کربن در سطح مشترک اتصال، درجه‌بندی ناحیه پیوند با استفاده از کربن و همچنین ایجاد درگیری مکانیکی به‌وسیله‌ی پله معکوس، تاثیرات مثبتی بر استحکام اتصال دارند. به‌طوریکه با درجه‌بندی ناحیه هم‌پوشانی به‌وسیله کربن و شیشه، توزیع تنش برشی و پوسته‌کنی یکنواخت‌تر شده و بار و جابجایی شکست نسبت به نمونه مرجع که دارای استحکام برشی 1.92 کیلونیوتن است، 34% افزایش یافته است. ایجاد پله معکوس در چسبنده‌ها موجب تغییر مود شکست می‌شود. به‌طوریکه وجود یک پله، 40% و قرارگیری کربن در فصل مشترک آن، 112% استحکام را افزایش داده است. اما بیشترین افزایش استحکام و جابجایی شکست با استفاده از دو پله معکوس و همچنین الیاف کربن در فصل مشترک دو چسبنده، به میزان قابل توجه 172% به‌دست آمده است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Strength improvement of composite-steel lap joint by grading the joint area with carbon and glass fiber and also mechanical interference by reverse step

نویسندگان [English]

  • Alireza Dadian 1
  • Saeed Rahnama 2
  • Abbas Zolfaghari 3

1 Department of Mechanical Engineering, Birjand University, Birjand, Iran.

2 Department of Mechanical Engineering, Birjand University, Birjand, Iran.

3 Department of Mechanical Engineering, Noshirvani University of technology, Babol, Iran.

چکیده [English]

Effectively joining metals and composites in an efficient manner is challenging due to their dissimilar physical compositions and mechanical properties. Failure of bonded joints is generally strongly influenced by the non-uniform distribution of stresses and strains that usually with the maximum value, commonly located near the ends of the overlaps. In this study, carbon is used as a reinforcing element in the adhesive layer and to improve the distribution of stress, properties are graded by fibers along the overlap. Also, using a new method, the effect of the reverse step on joint strength has been investigated. In addition, finite element modeling is used to express the distribution of shear and peel stresses in the adhesive layer and also to analyze the reasons for increasing joint strength in stepped specimens. Use of carbon at the joint surface, grading of the joint area and mechanical interference through reverse steps, have positive effects on strength. By grading the overlap by carbon and glass, the distribution of shear and peel stress have become more uniform and load and displacement of failure compared to the base specimen, which has a shear strength of 1.92 kN, increased by 34%. Creating the reverse step changes the failure mode. The presence of one step 40%, and the placement of carbon at the joint interface of that, has increased 112% of strength. But the greatest increase in strength and displacement failure is achieved using two reverse steps and carbon in the joint surface, by a significant amount of 172%.

کلیدواژه‌ها [English]

  • Functionally graded joint
  • Co-cured method
  • Lap joint
  • Mechanical interference
  • Reverse step

[1]   Cruz, P. L., “Experimental and Numerical Study on Bolted/Bonded Composite Joints for Aircraft,” Ph.D. Thesis, Carleton University, Canada, 2016.

[2]   Da Silva, L. F. M., Ochsner, A. and Adams, R. D., “Handbook of Adhesion Technology,” Heidelberg, Springer, 2011.

[3]   Lang, T. P. and Mallick, P. K., “Effect of Spew Geometry on Stresses in Single Lap Adhesive Joints,” International Journal of Adhesion & Adhesives, Vol. 18, pp. 167–177, 1998.

[4]   Frostig, Y., Thomsen, O. T. and Mortensen, F., “Analysis of Adhesive-Bonded Joints Squareend and Spew-Fillet-High-Order Theory Approach,” Journal of Engineering Mechanics, Vol. 125, pp. 1289–1307, 1999.

[5]   Belingardi, G., Goglio, L. and Tarditi, A., “Investigating the Effect of Spew and Chamfer Size on the Stresses in Metal/Plastics Adhesive Joints,” International Journal of Adhesion & Adhesives, Vol. 22, pp. 273–282, 2002.

[6]   Da Silva, L. F. M. and Adams, R. D., “Adhesive Joints at High and Low Temperatures Using Similar and Dissimilar Adherends and Dual Adhesives,” International Journal of Adhesion & Adhesives, Vol. 27, pp. 216–226, 2007.

[7]   Da Silva, L. F. M. and Adams, R. D., “Joint Strength Predictions for Adhesive Joints to be Used Over a Wide Temperature Range,” International Journal of Adhesion & Adhesives, Vol. 27, pp. 362–379, 2007.

[8]   Adams, R. D. and Harris, J. A., “The Influence of Local Geometry on the Strength of Adhesive Joints,” International Journal of Adhesion & Adhesives, Vol. 7, pp. 69–80, 1987.

[9]   Adams, R. D., Comyn, J. and Wake, W. C., “Strucutural Adhesive Joints in Engineering,” Chapman & Hall, London, 2nd edition, 1997.

 

[10]   Zhao, X., Adams, R. D. and Da Silva, L. F. M., “Single Lap Joints with Rounded Adherend Corners: Experimental Results and Strength Predictions,” Journal of Adhesion Science and  Technology, Vol. 25, pp. 837–856, 2011.

[11]   Zhao, X., Adams, R. D. and Da Silva, L. F. M., “Single Lap Joints with Rounded Adherend Corners: Stress and Strain Analysis,” Journal of Adhesion Science and  Technology, Vol. 25, pp. 819–836, 2011

[12]   Rispler, A. R., Tong, L., Steven, G. P. and Wisnom, M. R., “Shape Optimisation of Adhesive Fillets,” International Journal of Adhesion & Adhesives, Vol. 20, pp. 221–231, 2000.

[13]   Da Silva, L. F. M. and Adams, R. D., “Techniques to Reduce the Peel Stresses in Adhesive Joints with Composites,” International Journal of Adhesion & Adhesives, Vol. 27, pp. 227–35, 2000.

[14]   Marques, E. A. S. and Da Silva, L. F. M., “Joint Strength Optimization of Adhesively Bonded Patches,” The Journal of Adhesion, Vol. 84, pp. 917–936, 2008.

[15]   Jansen, B. J. P., Tamminga, K.Y., Meijer, H.E.H. and Lemstra, P.J., “Preparation of Thermoset Rubbery Epoxy Particles as Novel Toughening Modifiers for Glassy Epoxy Resins,” Polymer, Vol. 40, pp. 5601-5607, 1999.

[16]   Kaji, M. R., Farahani, M. R. and Ansari, M., “Investigation on the Effects of the Number and Diameter of the Wires on the Strength of the Reinforced Adhesive Joint of Composites,” In Persian, Iranian Journal of Manufacturing Engineering, Vol. 2, No, 4, pp. 28-35, 2015.

[17]   Khalili, S. M. R., Shokuhfar, A., Hoseini, S. D., Bidkhori, M. and Mittal, R. K., “Experimental Study of the Influence of Adhesive Reinforcement in Lap Joints for Composite Structures Subjected to Mechanical Loads,” International Journal of Adhesion & Adhesives, Vol. 28, pp. 436-444, 2008.

[18]   Parkes, P. N., Butler, R., Meyer, J. and De Oliveira, A., “Static Strength of Metal-Composite Joints with Penetrative Reinforcement,” Composite Structures, Vol. 118, pp. 250-256, 2014.

[19]   Shahrohkinasab, S.,  Sahraeeyan, R. and Sabet, A., “Assessment of Mixed Adhesive in Single lap and Peel Joint with Composite Substrate,” In Persian, Journal of Science and Technology of Composites, Vol. 4, No. 2, pp. 189-194, 2014.

[20]   Marques, E. A. S., Magalhães D. N. M. and Da Silva, L. F. M., “Experimental Study of Silicone Epoxy Dual Adhesive Joints for High Temperature Aerospace Applications,” Mater-Wiss Werkstofftech, Vol. 42, pp. 471–477, 2011.

[21]   Da Silva, L. F. M. and Lopes, M. J. C. Q., “Joint Strength Optimization by the Mixed-Adhesive Technique,” International Journal of Adhesion & Adhesion, Vol. 29, pp. 509–514, 2009.

[22]   Kumar, S. and Pandey, P.C., “Behaviour of Bi-Adhesive Joints,” Journal of Adhesion Science and Technology, Vol. 24, pp. 1251–1281, 2010.

[23]   Carbas, R. J. C., Da Silva, L. F. M. and Andrés, L. F. S.,  “Functionally Graded Adhesive Joints by Graded Mixing of Nanoparticles”, International Journal of Adhesion & Adhesives, Vol. 76, pp. 30–37, 2017.

[24]   E Glass Woven Roving 200, Technical Data Sheet, AMP Composites, 2009.

[25]   CWUTM 300, Carbon Wrap Unidirectional, Technical Data Sheet, AFZIR Composites, 2008.

[26]   EPON™ Resin 828, Technical Data Sheet, Hexion, 2005.

[27]   Standard Test Method for Lap Shear Adhesion for Fiber Reinforced Plastic (FRP) Bonding, Annual Book of ASTM Standard, D 5868 – 01, 2001.

 

[28]   R. J. C. Carbas, L. F. M. Da Silva, and L. F. S. Andrés, “Functionally Ggraded Adhesive Joints by Graded Mixing of Nanoparticles”, International Journal of Adhesion & Adhesives, Vol. 76, pp. 30–37, 2017.

[29]   R. Breto, A. Chiminelli, E. Duvivier, M. Lizaranzu, and M. A. Jimenez, “Finite Element Analysis of Functionally Graded Bond-Lines for Metal/Composite Joints”, The Journal of Adhesion, Vol. 91, pp. 920–936, 2015.

[30]   Standard Practice for Classifying Failure Modes in Fiber-Reinforced-Plastic (FRP) Joints, Annual Book of ASTM Standard, D 5573 – 99, 2005.