Determination of Buckling Loads of Tilted Buckled Column with Varying Flexural Rigidity Using Variational Iteration Method

Author(s):  
Mehmet Tarik Atay
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Xingzhuang Zhao

AbstractCompressive structural members can be locally damaged by overloading, corrosion, car crash and fire. In this work, a continuous diffused crack model is proposed to study the static stability of Euler–Bernoulli rectangular column-like structures under different boundary conditions. The governing differential equation is formulated by adopting a diffused crack model. The powerful variational iteration method is implemented to find the approximate analytical buckling modes and buckling loads based on the buckling response of the intact column. A novel generalized Lagrange multiplier is derived. The proposed method incorporates the effects of the crack width into consideration when deriving the buckling modes. The stability equation allows addressing the influences of multiple damages and can be applied to both concentrated and distributed cracks. The famous Rayleigh–Ritz method is utilized to verify the computed buckling loads. The proposed diffused crack model and the application with VIM is efficient and accurate for handling buckling problems of cracked columns under different boundary conditions.


Author(s):  
N. Okiotor ◽  
F. Ogunfiditimi ◽  
M. O. Durojaye

In this study, the Variational Iteration Method (VIM) is applied in finding the solution of differential equations with emphasis laid on the choice of the Lagrange multiplier used while employing VIM. Building on existing methods and variational theories, the operator D-Method and integrating factor are employed in certain aspects in the determination of exact Lagrange multiplier for VIM. When results of the computed exact Lagrange multiplier were compared with results of approximate Lagrange multiplier, it was observed that the computed exact Lagrange multiplier reduced significantly the number of iterations required to get a good approximate result, and in some cases the result converged to the exact solution after a single iteration. Evaluations are carried out using MAPLE Software.


Author(s):  
Gholamreza Hashemi ◽  
Morteza Ahmadi

This paper uses the variational iteration method to study nonlinear oscillator, and He’s amplitude–frequency formulation is adopted here as a good initial guess. In general, the ability of amplitude–frequency formulation to present reasonable and precision results makes it a reliable method, especially in oscillation systems. In addition, simplicity in the determination of the frequency of the system is one of the distinctive merits in this method. On the other hand, it is difficult to attain higher accurate solutions or higher order solutions in amplitude–frequency formulation. Thus, to overcome this hardship, one can select amplitude–frequency formulation as an initial guess in variational iteration method; this not only noticeably improves the accuracy and efficiency of variational iteration method (improved variational iteration method) but also accomplishing higher order solutions is feasible. Moreover, the more precise the frequency of the initial guess of variational iteration method, the more dominant the final results of variational iteration method. To show the ability and precision of this choice, some examples are presented and their results are compared to variational iteration method, amplitude–frequency formulation, energy balance method, and fourth Runge-Kutta’s numerical method. The resultant graphs and charts show an excellent agreement to this choice. In fact, the choice of amplitude–frequency formulation as an initial guess not only improves various aspects of the variational iteration method but also it distinguishes decline the relatively complex trend of calculating of initial guess compared to other ways.


2010 ◽  
Vol 65 (5) ◽  
pp. 418-430 ◽  
Author(s):  
Ahmet Yildirim

In this paper, an application of He’s variational iteration method is applied to solve nonlinear integro-differential equations. Some examples are given to illustrate the effectiveness of the method. The results show that the method provides a straightforward and powerful mathematical tool for solving various nonlinear integro-differential equations


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