حل صفحات میندلین به روش رهایی پویا

نوع مقاله : مقاله علمی

نویسندگان
1 استادیار، گروه مهندسی عمران، دانشکده فنی و مهندسی، مجتمع آموزش عالی گناباد، گناباد، ایران
2 استادیار، گروه مهندسی مکانیک، دانشکده فنی و مهندسی، مجتمع آموزش عالی گناباد، گناباد، ایران
چکیده
نظریه صفحه‌ی میندلین، که شامل اثرات تغییر شکل برشی است، برای اطمینان از مدل‌سازی دقیق صفحات نسبتاً ضخیم به کار می‌رود. این مقاله به بررسی کارایی روش‌های مختلف رهایی پویا برای تحلیل الاستیک صفحات میندلین می‌پردازد. هدف اصلی، ارزیابی مزایای دوازده شیوه‌ی رهایی است. تفاوت این راه‌کارها در چگونگی تعیین پارامترهای ساختگی مانند میرایی و جرم می‌باشد که برای همگرایی رهایی پویا لازم هستند. این مطالعه بر ارزیابی این روش‌ها بر اساس پایداری عددی، سرعت همگرایی و کارایی محاسباتی تمرکز دارد. چندین نمونه از صفحات میندلین با هندسه‌ها و شرایط مرزی متنوع برای مقایسه‌ی عملکرد راه‌کارهای گوناگون رهایی پویا حل می‌شوند. با توجه به تنوع نمونه‌های حل‌شده، می‌توان از نتایج آن به ‌عنوان مسائل بنچمارک در حل صفحه‌های میندلینی بهره جست. معیارهای کلیدی، از جمله تعداد تکرارهای مورد نیاز برای همگرایی و کل زمان محاسباتی، برای هر روش ثبت شده‌اند. نتایج، تغییرات قابل توجهی در کارایی بین دوازده الگوریتم را نشان می‌دهد. به طوری که برخی دارای همگرایی سریعی هستند؛ در حالی که برخی دیگر به تکرارهای قابل توجهی بیشتری نیاز دارند. یک رتبه‌بندی جامع بر اساس این معیارهای محاسباتی ایجاد شده است که کارآمدترین و قوی‌ترین تکنیک‌ها را برای کاربردهای عملی شناسایی می‌کند. همچنین، این مطالعه حساسیت همگرایی رهایی پویا به انتخاب پارامترهای ساختگی را نشان می‌دهد. نتایج عددی، نمایانگر کارایی مناسب روش آندوود در زمان تحلیل و شیوه‌ی کمینه انرژی پسماند در شمار تکرارها برای تحلیل صفحات میندلینی است.
کلیدواژه‌ها
موضوعات

عنوان مقاله English

Analysis of Mindlin Plates by Dynamic Relaxation Method

نویسندگان English

Hossein Estiri 1
Mahdi Adineh 2
1 Assistant Professor, Department of Civil Engineering, University of Gonabad, Gonabad, Iran
2 Assistant Professor, Department of Mechanical Engineering, University of Gonabad, Gonabad, Iran
چکیده English

The Mindlin plate theory, which accounts for shear deformation effects, is employed to ensure accurate modeling of moderately thick plates. This paper investigates the efficiency of various dynamic relaxation methods for the elastic analysis of Mindlin plates. The main objective is to evaluate the advantages of twelve different relaxation schemes. The distinctions among these approaches lie in the determination of artificial parameters such as damping and mass, which are essential for the convergence of dynamic relaxation. The study focuses on assessing these methods based on numerical stability, convergence rate, and computational efficiency. Several Mindlin plate examples with diverse geometries and boundary conditions are solved to compare the performance of different dynamic relaxation techniques. Given the variety of the analyzed cases, the obtained results can serve as benchmark problems for Mindlin plate analysis. Key criteria, including the number of iterations required for convergence and the total computational time, are recorded for each method. The results reveal significant variations in efficiency among the twelve algorithms, with some exhibiting rapid convergence while others require considerably more iterations. A comprehensive ranking based on these computational metrics is established to identify the most efficient and robust techniques for practical applications. Furthermore, the study demonstrates the sensitivity of dynamic relaxation convergence to the selection of artificial parameters. Numerical results indicate that the Underwood method is efficient in terms of analysis time, while the minimum residual energy scheme achieves the fewest iterations for Mindlin plate analysis.



Several benchmark cases of Mindlin plates with diverse geometries and boundary conditions are solved to compare the performance of the proposed DR schemes. Given the variety of solved examples, the results can serve as benchmark problems for Mindlin plate analyses. Key metrics, including the number of iterations required for convergence and total computational time, are recorded for each method. The results reveal significant variations in efficiency among the twelve algorithms: some exhibit rapid convergence, while others demand substantially more iterations. A comprehensive ranking system is established based on these computational criteria, identifying the most efficient and robust techniques for practical applications.



Furthermore, this study highlights the sensitivity of dynamic relaxation convergence to the selection of fictitious parameters. Numerical results demonstrate the effectiveness of the Underwood method in computational time and the minimum residual energy technique in iteration count for analyzing Mindlin plates.

کلیدواژه‌ها English

dynamic relaxation
Mindlin plate
mass
damping
time step

اصل مقاله

[1] O. C. Zienkiewicz and R. L. Taylor, The Finite Element Method for Solid and Structural Mechanics. Oxford, UK: Butterworth-Heinemann, 2005.
[2] J. N. Reddy, Theory and Analysis of Elastic Plates and Shells. Boca Raton, FL, USA: CRC Press, 2006.
[3] S. Timoshenko and S. Woinowsky-Krieger, Theory of Plates and Shells. New York, NY, USA: McGraw-Hill, 1959.
[4] G.-R. Liu and Y.-T. Gu, An Introduction to Meshfree Methods and Their Programming. Berlin, Germany: Springer, 2005.
[5] A. S. Day, “An introduction to dynamic relaxation,” The Engineer, Vol. 219, pp. 218–221, 1965.
[6] J. Otter et al., “Discussion: Dynamic relaxation,” in ICE Proceedings, Vol. 37, No. 4, pp. 723–750, 1967.
[7] M. Rezaiee-Pajand and J. Alamatian, “The dynamic relaxation method using new formulation for fictitious mass and damping,” Structural Engineering and Mechanics, Vol. 34, No. 1, pp. 109–133, 2010, doi: 10.12989/sem.2010.34.1.109.
[8] P. Underwood, “Dynamic relaxation (in structural transient analysis),” in Computational Methods for Transient Analysis. Amsterdam, The Netherlands: North-Holland, 1983, pp. 245–265.
[9] M. Kadkhodayan, J. Alamatian, and G. J. Turvey, “A new fictitious time for the dynamic relaxation (DXDR) method,” International Journal for Numerical Methods in Engineering, Vol. 74, No. 6, pp. 996–1018, 2008, doi: 10.1002/nme.2201.
[10] M. R. Barnes, “Form-finding and analysis of prestressed nets and membranes,” Computers & Structures, Vol. 30, No. 3, pp. 685–695, 1988, doi: 10.1016/0045-7949(88)90304-5.
[11] M. Rezaiee-Pajand and H. Estiri, “Geometrically nonlinear analysis of shells by various dynamic relaxation methods,” World Journal of Engineering, Vol. 14, No. 5, pp. 381–405, 2017, doi: 10.1108/WJE-10-2016-0109.
[12] M. Rezaiee-Pajand and H. Estiri, “A comparison of large deflection analysis of bending plates by dynamic relaxation,” Periodica Polytechnica Civil Engineering, 2016, doi: 10.3311/PPci.8728.
[13] M. Papadrakakis, “A method for the automatic evaluation of the dynamic relaxation parameters,” Computer Methods in Applied Mechanics and Engineering, Vol. 25, No. 1, pp. 35–48, 1981, doi: 10.1016/0045-7825(81)90066-9.
[14] L. C. Zhang, M. Kadkhodayan, and Y. W. Mai, “Development of the maDR method,” Computers & Structures, Vol. 52, No. 1, pp. 1–8, 1994, doi: 10.1016/0045-7949(94)90249-6.
[15] P. Cundall, “Explicit finite-difference methods in geomechanics,” in Proc. 2nd Int. Conf. on Numerical Methods in Geomechanics, Blacksburg, VA, USA, 1976.
[16] B. H. V. Topping and P. Ivanyi, Computer Aided Design of Cable Membrane Structures. Scotland: Saxe-Coburg Publications, 2008, ch. Dynamic Relaxation, pp. 39–84.
[17] M. Rezaiee-Pajand, S. R. Sarafrazi, and H. Rezaiee, “Efficiency of dynamic relaxation methods in nonlinear analysis of truss and frame structures,” Computers & Structures, Vol. 112–113, pp. 295–310, 2012, doi: 10.1016/j.compstruc.2012.08.007.
[18] M. Rezaiee-Pajand and H. Estiri, “Comparative analysis of three-dimensional frames by dynamic relaxation methods,” Mechanics of Advanced Materials and Structures, pp. 1–16, 2017, doi: 10.1080/15376494.2017.1285462.
[19] M. Rezaiee-Pajand, H. Estiri, and M. Mohammadi-Khatami, “Creating better dynamic relaxation methods,” Engineering Computations, Vol. 36, No. 5, pp. 1483–1521, 2019, doi: 10.1108/EC-08-2018-0384.
[20] S. R. Sarafrazi and S. F. Labbafi, “Dynamic relaxation with concentrated damping,” Modares Civil Engineering Journal, Vol. 17, No. 3, pp. 146–156, 2017.
[21] A. Zardi and J. Alamatian, “A novel formulation for fictitious mass in viscous dynamic relaxation method,” Ferdowsi Civil Engineering Journal, Vol. 31, No. 1, pp. 15–30, 2018 (in Persian), doi: 10.22067/civil.v31i1.53685.
[22] M. Abbasi, A. Namdchi, and J. Alamatian, “A new formulation for kinetic dynamic relaxation method based on Lagrange interpolation,” Sharif Journal of Civil Engineering, Vol. 36, No. 2, pp. 61–69, 2021 (in Persian), doi: 10.24200/j30.2020.53836.2603.
[23] H. Estiri and A. Baghban, “Finding limit points by dynamic relaxation method,” Journal of Structure & Steel Research, Vol. 16, No. 37, pp. 21–35, 2023.
[24] H. Estiri and A. Baghban, “Tracing equilibrium paths using the dynamic relaxation method,” Journal of Structural Mechanics and Solids, Vol. 12, No. 6, pp. 35–48, 2022 (in Persian), doi: 10.22044/jsfm.2023.12271.3646.
[25] S. Qiang, “An adaptive dynamic relaxation method for nonlinear problems,” Computers & Structures, Vol. 30, No. 4, pp. 855–859, 1988, doi: 10.1016/0045-7949(88)90117-4.
[26] L. G. Zhang and T. X. Yu, “Modified adaptive dynamic relaxation method and its application to elastic–plastic bending and wrinkling of circular plates,” Computers & Structures, Vol. 33, No. 2, pp. 609–614, 1989, doi: 10.1016/0045-7949(89)90035-7.
[27] M. Rezaiee-Pajand and M. Taghavian Hakkak, “Nonlinear analysis of truss structures using dynamic relaxation,” International Journal of Engineering, Vol. 19, No. 1, pp. 11–22, 2006.
[28] M. Rezaiee-Pajand, M. Kadkhodayan, and J. Alamatian, “Timestep selection for dynamic relaxation method,” Mechanics Based Design of Structures and Machines, Vol. 40, No. 1, pp. 42–72, 2012, doi: 10.1080/15397734.2011.599311.
[29] M. Rezaiee-Pajand and S. R. Sarafrazi, “Nonlinear structural analysis using dynamic relaxation method with improved convergence rate,” International Journal of Computational Methods, Vol. 7, No. 4, pp. 627–654, 2010, doi: 10.1142/S0219876210002386.
[30] M. Rezaiee-Pajand and S. R. Sarafrazi, “Nonlinear dynamic structural analysis using dynamic relaxation with zero damping,” Computers & Structures, Vol. 89, nos. 13–14, pp. 1274–1285, 2011, doi: 10.1016/j.compstruc.2011.04.005.
 
 

  • تاریخ دریافت 08 تیر 1404
  • تاریخ بازنگری 22 شهریور 1404
  • تاریخ پذیرش 29 مهر 1404
  • تاریخ اولین انتشار 29 مهر 1404
  • تاریخ انتشار 01 بهمن 1404