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Soleymani F.,Islamic Azad University at Zahedan
Mathematical and Computer Modelling | Year: 2011

It is widely known that when the order of root solvers increases, their accuracy comes up as well. In light of this, most of the researchers in this field of study have tried to increase the order of known schemes for obtaining optimal three-step eighth-order methods in which there are four evaluations per iteration. The aim of this article is to challenge this standpoint when the starting points are in the vicinity of the root, but not so close. Toward this end, a novel method of order six with the same number of evaluations per iteration is suggested and demonstrated while its accuracy is better than the accuracy of optimal eighth-order schemes for such initial guesses. The superiority of the developed technique is confirmed by numerical examples. © 2010 Elsevier Ltd. Source

Narmashiri K.,Islamic Azad University at Zahedan | Ramli Sulong N.H.,University of Malaya | Jumaat M.Z.,University of Malaya
Construction and Building Materials | Year: 2012

This paper reports the experimental and numerical investigations on the Carbon Fibre Reinforced Polymer (CFRP) failure analysis and structural behaviour of the CFRP flexural strengthened steel I-beams. Understanding the CFRP failure modes is useful to find solutions for preventing or retarding the failures. One non-strengthened control beam and twelve strengthened beams using different types and dimensions of CFRP strips in both experimental test and simulation modelling studies were investigated. In the experimental test, four-point bending method with static gradual loading was applied. To simulate the specimens, the ANSYS software in full three dimensional (3D) modelling case and non-linear analysis method was utilized. The results show the CFRP failure modes used in flexural strengthening of steel I-beams include below point load splitting (BS), below point load debonding (BD), end delamination (EDL), and end debonding (ED). The occurrences and sequences of CFRP failure modes depended on the strengthening schedule. The structural performance of the CFRP strengthened steel beams also varied according to the strengthening specifications investigated in this research. © 2011 Elsevier Ltd. All rights reserved. Source

Soleymani F.,Islamic Azad University at Zahedan
Japan Journal of Industrial and Applied Mathematics | Year: 2013

This paper opens the issue of solving a nonlinear equation by iterative methods in which no derivative is required per iteration. Hence, an optimal class of three-step methods without memory is demonstrated, where each of its elements (methods) requires only four function evaluations per iteration to achieve the eighth order of convergence. In order to verify the effectiveness of the proposed methods, we employ numerical examples. The attained results are consistent with the developed theory. We finally present an algorithm to capture all the real simple solutions of nonlinear functions in an interval. © 2013 The JJIAM Publishing Committee and Springer Japan. Source

Tohidi E.,Islamic Azad University at Zahedan | Kilicman A.,University Putra Malaysia
Mathematical Problems in Engineering | Year: 2013

A new collocation method is developed for solving BVPs which arise from the problems in calculus of variation. These BVPs result from the Euler-Lagrange equations, which are the necessary conditions of the extremums of problems in calculus of variation. The proposed method is based upon the Bernoulli polynomials approximation together with their operational matrix of differentiation. After imposing the collocation nodes to the main BVPs, we reduce the variational problems to the solution of algebraic equations. It should be noted that the robustness of operational matrices of differentiation with respect to the integration ones is shown through illustrative examples. Complete comparisons with other methods and superior results confirm the validity and applicability of the presented method. © 2013 Emran Tohidi and Adem Kiliçman. Source

Soleymani F.,Islamic Azad University at Zahedan
WSEAS Transactions on Information Science and Applications | Year: 2011

The calculation of derivatives of a function mostly takes up a great deal of time and even in some cases, such as the existing problems in engineering and optimization, is impossible to be evaluated directly. Accordingly, an accurate derivative-free class of three-step methods is suggested for solving f(x)=0. The proposed three-step technique comprises four evaluations of the function per iteration. The analytical proof of the main contribution is given. And finally, the accuracy of the developed techniques is tested numerically by solving numerical examples. Source

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