پیوندهای مفید
آمار
| تعداد نشریات | 8 |
| تعداد شمارهها | 443 |
| تعداد مقالات | 5,689 |
| تعداد مشاهده مقاله | 7,846,695 |
| تعداد دریافت فایل اصل مقاله | 6,409,068 |
تحلیل ناپایداری دینامیکی تیر ساندویچی ضخیم با هسته انعطافپذیر تابعی تحت اثر نیروی تعقیب کننده | ||
| نشریه مهندسی مکانیک امیرکبیر | ||
| مقاله 11، دوره 53، شماره 2، اردیبهشت 1400، صفحه 863-880 اصل مقاله (3.02 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/mej.2019.16239.6308 | ||
| نویسندگان | ||
| غلامحسن پایگانه* 1؛ کرامت ملک زاده فرد2؛ فهیمه راشد سقاواز1 | ||
| 1دانشکده مهندسی مکانیک، دانشگاه تربیت دبیر شهید رجایی، تهران، ایران | ||
| 2دانشکده مهندسی هوافضا، دانشگاه صنعتی مالک اشتر، تهران، ایران | ||
| چکیده | ||
| سازههای هوایی هنگامیکه تحت اثر نیروهای ناپایستار، بهویژه نیروهای تعقیبکننده قرار میگیرند، ممکن است علاوه بر ناپایداری استاتیکی در معرض ناپایداری دینامیکی (پدیده فلاتر) نیز قرار بگیرند. بههمین علت ضروری است، سازه بهنحوی طراحی گردد، تا از وقوع ناپایداریهای استاتیکی و دینامیکی جلوگیری شود. در این مقاله به کمک تئوری مرتبه بالای تیرهای ساندویچی جدید برای اولین بار، ناپایداری دینامیکی تیر ساندویچی ضخیم با هسته انعطافپذیر تابعی تحت اثر نیروی تعقیب کننده مورد بررسی قرار گرفته است. تیر ساندویچی از دو رویه و یک هسته انعطافپذیر تشکیل شده است. سطح مشترک هسته با رویهها شامل اتصال کامل است، که قابلیت تحمل تنشهای برشی و عمودی را دارا میباشد. تیر ساندویچی بهصورت الاستیک خطی با جابجاییها و چرخشهای کوچک در نظر گرفته شده است. معادلات حرکت تیر ساندویچی مرتبه بالا، تحت اثر نیروی تعقیبکننده به کمک اصل همیلتون استخراج شده است. با اعمال شرایط مرزی و با کمک روش حل عددی تربیع مربعات، پدیده فلاتر مورد بررسی قرار گرفته است. علاوه بر صحهگذاری نتایج، اثر پارامترهای مختلف هندسی و موادی تیر نیز بر آستانه نیروی فلاتر مورد مطالعه قرار گرفته است. نتایج نشان میدهد، برای تیرهای بلند، مقدار نیروی تعقیبکننده آستانه پدیده فلاتر به نتایج متناظر در تیر تیموشنکو میل میکند. | ||
| کلیدواژهها | ||
| سازههای هوایی؛ سازههای ساندویچی؛ ناپایداری دینامیکی؛ روش حل عددی؛ هسته انعطافپذیر تابعی | ||
| عنوان مقاله [English] | ||
| Analysis of dynamic instability in sandwich thick beams with flexible functional core subjected to a follower force | ||
| نویسندگان [English] | ||
| Gholamhasan Payganeh1؛ Keramat Malekzadeh Fard2؛ Fahimeh Rashed Saghavaz1 | ||
| 1Department of Mechanical Engineering, Shahid Rajaee Teacher Training University (SRTTU), Tehran, Iran | ||
| 2Aerospace research institute, Malekashtar university of Technology, Tehran, Iran | ||
| چکیده [English] | ||
| Aerial structures under non-conservative forces especially follower loads, may be exposed to dynamic or static instabilities. Thus, it is essential to design these structures so that it would prevent this phenomenon. In this paper, for the first time, dynamic instability of a thick sandwich beam with flexible core under follower force is considered using high-order theory of sandwich beams. In the present paper, shear and normal core plate stresses are also considered, which have been ignored in higher-order sandwich panel theory and improved higher-order sandwich panel theory. The sandwich beam consists of two surfaces and a flexible core. The common surface of the core with the surfaces comprises a complete connection, capable of withstanding shear and vertical stresses. Sandwich beam is considered as a linear elastic structure with small rotations and deformations. Equations of Motion of high-order sandwich beams under follower force, are derived using Hamilton’s principle. The Beam fluttering phenomenon is investigated by applying boundary conditions and using a generalized differential quadrature method. in addition to the verification of results, effects of the beam’s geometry and mechanical parameters have been studied. These results revealed that the threshold flutter force of the sandwich beam is similar to Timoshenko one. | ||
| کلیدواژهها [English] | ||
| Pneumatic structures, Sandwich structures, Dynamic instability, Numerical solution method, Flexible functional core | ||
| مراجع | ||
|
[1] E. Nikolai. On the stability of the rectilinear form of equilibrium of a bar in compression and torsion. Izv Leningr Politech. (1928).
[2] M. Beck. Die Knicklast des einseitig eingespannten, tangential gedrucktenStabes (The buckling load of the cantilever column subjected to tangential force). Z. Angew. Math. Phys. 3 (1952) 225-228.
[3] H. H. E. Leipholz. On the sufficiency of the energy criterion for the stability of certain nonconservative systems of the follower-load type. Journal of Applied Mechanics, 39(1972) 717–722.
[4] H. H. E. Leipholz. On principles of stationary for non-self-adjoint rod problems. Computer Methods in Applied Mechanics, 59(1986) 215- 226.
[5] R.C. Kar, W. Hauger. Stability of a pretwisted tapered cantilever beam subjected to dissipative and follower forces. Journal of Sound and Vibration, 81(1982) 565-573.
[6] Q. Chen, P. Qiao. Post-buckling Behavior of Imperfect Laminated Composite Plates with Rotationally-restrained Edges. Composite Structures, 125 (2015) 117-126.
[7] M. Damghani, D. Kennedy, C. Featherston. Global buckling of composite plates containing rectangular delaminations using exact stiffness analysis and smearing method. Computers & Structures, 134 (2014) 32-47.
[8] G. He, X. Yang. Finite element analysis for buckling of two-layer composite beams using Reddy’s higher order beam theory; Finite Elements in Analysis and Design, 83(2014) 49-57.
[9] C. W. Yap, G. B. Chai. Analytical and numerical studies on the buckling of delaminated composite beams. Composite Structures, 80(2007) 307-319.
[10] S. Katz, S. Givli. The post-buckling behavior of a beam constrained by springy walls. Journal of the Mechanics and Physics of Solids, 78 (2015)443-466.
[11] X. Li, H. L. Lv, G. C. Zhang, B. D. Ding. Seismic behavior of replaceable steel truss coupling beams with buckling restrained webs, Journal of Constructional Steel Research, 104 (2015) 167-176.
[12] A. Genoese, A. Genoese, A. Bilotta, G. Garcea. Buckling analysis through a generalized beam model including section distortions. Thin-Walled Structures, 85 (2014) 125-141.
[13] N.S. Trahair. Bending and buckling of tapered steel beam structures. Engineering Structures, 59 (2014) 229-237.
[14] V. V. Bolotin. The dynamic Stability of elastic systems; Holden; Day, INC. London. (1964).
[15] H. Ziegler. Die Stabilitltskriterien der Elastomechanik; Ing.-Arch, 20(1952) 49-56.
[16] C. D. Bailey, James L. Haines. Vibration and stability of non-conservative follower force systems. Computer Methods In Applied Mechanics And Engineering, 26 (1981) 1-31.
[17] Q. S. Li. Stability of non-uniform columns under the combined action of concentrated follower forces and variably distributed loads. Journal of Constructional Steel research, 64 (2008) 367-376.
[18] H. S. Alkhaldia, I. A. Alshaikha, R. A.Mallouhb, O. Ghazalb. Closed-form solution of large deflection of a spring-hinged beam subjected to non-conservative force and tip end moment. European Journal of Mechanics. 47 (2014) 271–279.
[19] P.M. Culkowski, H. Reismann. Plate buckling due to follower edge forces. Journal of Applied Mechanics, 44 (1977) 768-769.
[20] M. Farshad. Stability of cantilever plates subjected to biaxial sub-tangential loading. Journal of Sound and Vibration, 58(1978) 555-561.
[21] H.H.E. Leipholz. Stability of rectangular simply supported plate subjected to nonincreasing tangential follower forces. Journal of Applied Mechanics, 45 (1978) 223-224.
[22] H.H.E. Leipholz, F. Pfendt. Application of extended equations of Galerkin to stability problems of rectangular plates with free edges subjected to uniformly distributed follower forces. Computer Methods in Applied Mechanics and Engineering, 37(1983) 341-365.
[23] J.H. Kin, H.S. Kim. A study on the dynamic stability of plates under a follower force, Computers & Structures, 74(2000) 351-363.
[24] V. K. Goyala, R. K. Kapania. Dynamic stability of laminated beams subjected to non-conservative loading. Thin-Walled Structures, 46 (2008) 1359-1369.
[25] N. I. Kim, J. Lee. Divergence and flutter behavior of Beck’s type of laminated box beam. International Journal of Mechanical Sciences. 84 (2014) 91-101.
[26] M. J. Smyczynski, E. Magnucka-Blandzi. Static and dynamic stability of an axially compressed five-layer sandwich beam. Thin-Walled Structures. 90(2015) 23-30.
[27] H. Alidoost, J. Rezaeepazhand. Instability of a delaminated composite beam subjected to a concentrated follower force. Thin-Walled Structures. 120 (2017) 191-202.
[28] H. Alidoost, J. Rezaeepazhand. Flutter of multi-cracked laminated composite beams subjected to a non-conservative compressive load. Engineering Fracture Mechanics. 199 (2018) 1-12. (in Persian)
[29] Rui-Qiang Ma, Jian-Zheng Wei, Hui-Feng Tan, Zhi-Han Yan. Modal analysis of inflated membrane cone considering pressure follower force effect. Thin-Walled Structures. 132 (2018) 596-603.
[30] F. Rashed Saghavaz, GH. Payganeh, K. Malekzadeh. Flutter phenomenon in composite sandwich beams with flexible core under follower force. Steel and Composite Structures. 39 (2021) 615-630.
[31] K. Malekzadeh, M.R. Khalili, R.K. Mittal. Local and Global Damped Vibrations of Plates with a Viscoelastic Soft Flexible Core: An Improved High-order Approach. Journal of Sandwich Structures and Materials, 7 (2005) 431-456.
[32] Y. Frostig, O. T. Thomsen. high-order free vibrations of sandwich panels with a Flexible core. Journal of solid and structure, 41(2004)1697-1724.
[33] Y. Forsting, M. Baruch, O. Vinay, i. shteinman, i. higher-order theory for sandwich beams behavior with transversely flexible core. journal of engineering mechanics, 118 (1992)1026-1043.
[34] Y. Forsting, M. Baruch. free vibration of sandwich beams with a transverse flexible core: a higher order approach. journal of solids and vibration, 176 (1994)195-208.
[35] Frostig, Y. Buckling of sandwich panels with a flexible core‐high‐order theory. International Journal of Solids and Structures. 35 (1998)183–204.
[36] Reddy JN (2003) Mechanics of laminated composite plates and shells, theory and application. CRC Press, Boca Raton
[37] K. Malekzadeh, Impact Analysis on Compound Structures, Structural Impact Dynamics and Contact Theories, Almas Publishers, 1 (2016). (in Persian)
[38] Simitses, George J., and Dewey H. Hodges. Fundamentals of structural stability. Butterworth-Heinemann, 2006.
[39] Elishakoff, Isaac, and Itzhak Lottati. (1988). Divergence and flutter of nonconservative systems with intermediate support. Computer methods in applied mechanics and engineering, 66.2: 241-250.
[40] Shu, Chang. Differential quadrature and its application in engineering. Springer Science & Business Media, (2012).
| ||
|
آمار تعداد مشاهده مقاله: 986 تعداد دریافت فایل اصل مقاله: 1,129 |
||