نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکترا، مهندسی مکانیک، دانشگاه تربیت مدرس، تهرا ن.

2 استاد، مهندسی مکانیک، دانشگاه تربیت مدرس ، تهران.

10.22068/jstc.2021.124132.1649

چکیده

در این مقاله، مدلی تحلیلی براساس یک تکنیک معادل‌سازی جدید جهت پیش‌بینی کمانش کلی پوسته‌های ساندویچی مخروطی با هسته مشبک تحت بار محوری ارائه شده است. سازه ساندویچی از دو پوسته مخروطی داخلی و خارجی به همراه هسته‌ای مشبک از تقویت‌کننده‌ها که ما بین این دو پوسته قرار می‌گیرند، تشکیل می-شود. از یک روش تحلیلی-تقریبی معادل‌سازی توسعه‌یافته جهت معادل‌کردن هسته مشبک با یک پوسته کامپوزیتی استفاده می‌گردد. در ابتدا سفتی معادل هسته مشبک با استفاده از آنالیز نیرو و ممان بر روی یک سلول واحد از ساختار مشبک به دست می‌آید و سپس با استفاده از روش جمع آثار و به منظور دستیابی به سفتی کل سازه، با سفتی‌های پوسته‌ها جمع می-شوند. معادلات حاکم بر پوسته ساندویچی بر اساس تئوری کلاسیک دانل استخراج می‌شوند. از روش گالرکین برای محاسبه بارکمانش پوسته‌های ساندویچی مخروطی استفاده می‌شود. جهت صحت‌سنجی نتایج روش تحلیلی، یک مدل اجزای محدود سه‌بعدی نیز در نرم افزار آباکوس ساخته می-شود. مقایسه نتایج نشان داد که دو روش مذکور تطابق خوبی با هم داشته و مدل تحلیلی از دقت کافی برای پیش‌بینی رفتار کمانشی پوسته‌های مخروطی ساندویچی با هسته مشبک برخوردار است.

کلیدواژه‌ها

عنوان مقاله [English]

Global buckling load calculation of the of sandwich conical shells with lattice cores subjected to axial compression loading using a novel smeared method

نویسندگان [English]

  • Mehdi Zarei 1
  • Gholamhossein Rahimi 2

1 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran.

2 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran

چکیده [English]

In the present paper, an analytical model was presented according to a novel smeared stiffener approach in order to predict the global buckling load of composite sandwich conical shells with lattice core subjected to axial compression loading. The sandwich panel was made up of two skins and a lattice core. A smeared method was developed to approximate the lattice core with an equivalent composite shell. First, using the forces and moments analyses of a unit cell, the stiffness contribution due to the lattice were determined and then superimposed with those of the inner and outer skins in order to obtain the stiffness parameters of the whole panel. The governing equations were extracted according to the classical shell theory of Donnell type. Galerkin method was employed to obtain the buckling loads of the composite sandwich conical shells. A 3-D finite element model was also created using ABAQUS software in order to validate the analytical results. The comparison of the results indicated a good agreement between the two implemented methods and revealed that the proposed analytical model is accurate enough to predict the buckling behavior of sandwich conical shells with lattice core.

کلیدواژه‌ها [English]

  • Global buckling
  • Sandwich conical shell
  • Smeared method
  • Galerkin method
  • FEM
[1]Vasiliev, V.V. Barynin, V.A. Rasin, A.F., “Anisogrid lattice structures – Survey of development and application”, Composite Structures, Vol. 54, pp. 361-370, 2001.
[2] Slinchenko,  D. Verijenko, V.E., “Structural analysis of composite lattice shells of revolution on the basis of smearing stiffness”, Composite Structures, Vol. 54, pp. 341-348, 2001.
[3] Kidane,  S. Li, G. Helms, J. Pang, S.S. and Woldesenbet, E., “Buckling load analysis of grid stiffened composite cylinders”, Composites part B, Vol. 34, pp. 1-9, 2003.
[4] Jaunky,  N. Knight, N.F. Ambur, D.R., “Optimal Design of General Stiffened Composite Circular Cylinders for Global Buckling With Strength Constraints”, Composite Structures, Vol. 41, pp. 243-252, 1998.
[5] Wodesenbet,  E. Kidane,  S. Pang., “. Optimization for buckling loads of grid stiffened composite panels”, Composite Structures, Vol. 60, pp. 159-169, 2003.
[6] Yazdani, M. Rahimi, G.H. Afaghi Khatibi, A. and Hamzeh, S., “An experimental investigation into the buckling of GFRP stiffened shells under axial loading”, Scientific Research and Essays, Vol. 4, No. 9, pp. 914-920, 2009.
[7] Yazdani, M. and Rahimi, G.H., “The effects of helical ribs’ number and grid types on thebuckling of thin-walled GFRP-stiffened shells under axial loading”, Journal of Reinforced Plastics and Composites, Vol. 29, No. 17, pp. 2568-2575, 2010.
[8] Yazdani, M. and Rahimi, G.H., “The behavior of GFRP-stiffened and -unstiffened shells under cyclic axial loading and unloading”, Journal of Reinforced Plastics and Composites, Vol. 30, No. 5, pp. 440-445, 2011.
[9] Rahimi, G.H. Zandi, M. and Rasouli, S.F., “Analysis of the effect of stiffener profile on  the buckling strength in composite isogrid stiffened shell under axial loading”, Aerospace Science and Technology, Vol. 24, pp. 198-203, 2013.
[10] Shi,  S. Sun, Z. Ren, M. Chen, H. and Hu, X., “Buckling resistance of grid-stiffened carbon fiber thin-shell structures”, Composites part B, Vol. 45, pp. 888-896, 2013.
[11] Hemmatnezhad, M. Rahimi, G.H. and Ansari, R., “On the free vibrations of grid-stiffened compositecylindrical shells”, Acta Mechanca, Vol. 225, pp. 609-623, 2014.
[12] Hemmatnezhad, M. Rahimi, G.H. Tajik, M. and Pellicano, F., “Experimental, numerical and analytical investigation of free vibrational behavior of GFRP-stiffened composite cylindrical shells”, Composite Structures, Vol. 120, pp. 509-518, 2015.
[13] Ghasemi, M.A. Yazdani, M. and Hoseini, S.M., “Analysis of effective parametres on the buckling of grid stiffened composite shells based on first order shear deformation theory”, In Persian, Modares Mechnical Enginerring, Vol. 13, No. 10, pp. 51-61, 2013.
[14] Naderi, A.A. Rahimi, G.H. and Arefi, M., “Influence of fiber paths on buckling load of tailored conical shells”, Steel and Composite Structures, Vol. 16, No. 4, pp. 375-387, 2014.
[15] Zarei, M. and Rahimi, G.H., “Free Vibration Analysis of Grid Stiffened Composite Conical Shells”, In Persian, Journal of Science and Technology of Composites, Vol. 4, No. 1, pp. 1-8, 2017.
[16] Sun, F. Fan, H. Zhou, C. and Fang, D., “Equivalent analysis and failure prediction of quasi-isotropic composite sandwich cylinder with lattice core under uniaxial compression”, Composite Structures, Vol. 101, pp. 180-190, 2013.
[17] Xu, Y. Tong, Y. Liu, M. Suman, B.“A new effective smeared stiffener method for the global buckling analysis of grid stiffened composite panels.”, Composite Structures, Vol.158,pp.83–91, 2016.
[18]Tong,  L. Wang, T.K., “Simple solutions for buckling of laminated conical shells”, International Journal of Mechanical Sciences, Vol. 34, pp. 93-111, 1992.
[19]  Kazemi,  M.E. Kouchakzadeh, M.A. Shakouri., “Stability analysis of generally laminated conical shells with variable thickness under axial compression”, Mechanics of Advanced Materials and Structures, Vol. 14, pp. 1-14, 2018.
[20] Fares, M.E. Youssif, Y.G. and Alamir, AE. “Design and control optimization of composite laminated truncated conical shells for minimum dynamic response including transverse shear deformation” Composite Structures, Vol.64, pp.139–50, 2004.