Tracing structural static path by dynamic relaxation method

Authors

Civil Engineering, Faculty of Engineering, University of Gonabad, Gonabad, Iran

Abstract

The common dynamic relaxation algorithm (DR) does not have the ability to trace the static path. In these techniques, the jumps occur at the limit points. A variable load factor is used to fix this defect. Here, a new procedure is suggested to calculate the load factor. The authors’ relationship is achieved by minimizing external work and residual energy, simultaneously. It should be stated that the proposed load factor depends only on the DR artificial parameters. To show the ability of the new formulation, several truss and shell structures with nonlinear geometrically behavior are analyzed. All used methods are ranked by the number of iterations, numbers of convergence points and total duration analysis. Numerical solutions show the high efficiency of the new method. In other words, the authors' technique, in addition to good accuracy, has higher convergence rate, in comparison to the other strategies. On the other hand, the time duration of the proposed method to trace the static paths has been reduced appropriately compared to other techniques.

Keywords


[1] Alamatian J (2012) A new formulation for fictitious mass of the Dynamic Relaxation method with kinetic damping. Comput Struct 90–9142-54.
[2] Namadchi AH, Alamatian J (2016) Explicit dynamic analysis using dynamic relaxation method. Comput Struct 17591-99.
[3] Jung S, Kim T-Y, Yoo W-S (2018) Adaptive step-size control for dynamic relaxation using continuous kinetic damping. Math. Probl. Eng. 1-9.
[4] Rezaiee-Pajand M, Alamatian J (2008) Nonlinear dynamic analysis by dynamic relaxation method. Struct. Eng. Mech 28(5): 549-570.
[5] Rezaiee-Pajand M, Alamatian J (2010) The dynamic relaxation method using new formulation for fictitious mass and damping. Struct. Eng. Mech. 34(1): 109-133.
[6] Rezaiee-Pajand M, Kadkhodayan M, Alamatian J (2012) Timestep selection for dynamic relaxation method. Mech. Based Des. Struct. Mach. 40(1): 42-72.
[7] Rezaiee-Pajand M, Kadkhodayan M, Alamatian J, Zhang LC (2011) A new method of fictitious viscous damping determination for the dynamic relaxation method. Comput Struct 89(9–10): 783-794.
[8] Rezaiee-Pajand M, Sarafrazi SR (2010) Nonlinear structural analysis using dynamic relaxation method with improved convergence rate. Int. J. Comput. Methods 7(4): 627-654.
[9] Rezaiee-Pajand M, Sarafrazi SR (2011) Nonlinear dynamic structural analysis using dynamic relaxation with zero damping. Comput Struct 89(13–14): 1274-1285.
[10] Rezaiee-Pajand M, Taghavian Hakkak M (2006) Nonlinear analysis of truss structures using dynamic relaxation. Int. J. Eng. 19(1): 11-22.
[11] Rezaiee-Pajand M, Rezaee H (2012) Fictitious time step for the kinetic dynamic relaxation method. MAMS 21(8): 631-644.
[12] Rezaiee-Pajand M, Mohammadi-Khatami M (2019) A fast and accurate dynamic relaxation scheme. FSCE 13(1): 176-189.
[13] Rezaiee-Pajand M, Sarafrazi SR, Rezaiee H (2012) Efficiency of dynamic relaxation methods in nonlinear analysis of truss and frame structures. Comput Struct 112–113(0): 295-310.
]14[ گلمکانی م. ا, یوسفیان ثقی ع (1393) تحلیل غیر خطی ترموالاستیک صفحات گرد ساندویچی با هسته تابعی. مکانیک سازه‌‌ها و شاره‌‌ها 4(4): 127-142.
[15] Rezaiee-Pajand M, Estiri H (2016) A comparison of large deflection analysis of bending plates by dynamic relaxation. Period. Polytech.: Civ. Eng. 60(4): 619-645.
[16] Rezaiee-Pajand M, Estiri H (2017) Comparative analysis of three-dimensional frames by dynamic relaxation methods. MAMS 1-16.
[17] Rezaiee-Pajand M, Estiri H (2017) Geometrically nonlinear analysis of shells by various dynamic relaxation methods. World J. Eng. 14(5): 381-405.
]18[  سرافرازی س. ر, لبافی س. ف (1396) روش رهایی پویا با میرایی متمرکز. مهندسی عمران مدرس 17(3): 156-146.
[19] Zardi I, Alamatian J (2020) A new formulation for fictitious mass of viscous dynamic relaxation method. Mech. Based Des. Struct. Mach. 48(5): 542-567.
[20] Abbasi M, Namadchi AH, Alamatian J (2021) A new formulation for kinetic dynamic relaxation method based on the Lagrangian interpolation. Mech. Based Des. Struct. Mach. 1-15.
[21] Lee KS, Han SE, Park T (2011) A simple explicit arc-length method using the dynamic relaxation method with kinetic damping. Comput Struct 89(1–2): 216-233.
[22] Rezaiee-Pajand M, Alamatian J (2011) Automatic DR structural analysis of snap-through and snap-back using optimized load increments. J. Struct. Eng. 137(1): 109-116.
[23] Alamatian J (2013) Displacement-based methods for calculating the buckling load and tracing the post-buckling regions with dynamic relaxation method. Comput Struct 114–11584-97.
[24] Lee K-S, Han S-E, Hong J-W (2014) Post-buckling analysis of space frames using concept of hybrid arc-length methods. Int J Non Linear Mech 58(0): 76-88.
]25[ علامتیان ج, حسینی نژاد گوشیک س. م (1398) روش رهایی پویا برای محاسبه بار کمانشی قاب‌ها. نشریه مهندسی عمران و محیط زیست دانشگاه تبریز 49(96): 65-74.
[26] Rezaiee-Pajand M, Estiri H (2020) Finding buckling points for nonlinear structures by dynamic relaxation scheme. FSCE 14(1): 23-61.
[27] Rezaiee-Pajand M, Mohammadi-Khatami M (2021) Nonlinear analysis of cable structures using the dynamic relaxation method. FSCE 15(1): 253-274.
[28] Underwood P (1983) Dynamic relaxation (in structural transient analysis). Computational Methods for Transient Analysis(A 84-29160 12-64) Amsterdam, North-Holland 245-265.
[29] Zhang LG, Yu TX (1989) Modified adaptive dynamic relaxation method and its application to elastic-plastic bending and wrinkling of circular plates. Comput Struct 33(2): 609-614.
[30] Rezaiee-Pajand M, Estiri H (2016) Finding equilibrium paths by minimizing external work in dynamic relaxation method. Appl. Math. Model. 40(23–24): 10300-10322.
[31] Rezaiee-Pajand M, Estiri H (2016) Computing the structural buckling limit load by using dynamic relaxation method. Int J Non Linear Mech 81245-260.
[32] Meek JL, Tan HS (1984) Geometrically nonlinear analysis of space frames by an incremental iterative technique. Comput Methods Appl Mech Eng. 47(3): 261-282.