İnşaat Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/395
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Conference Object On the Mechanical and Elastic Properties of Anisotropic Engineering Materials Based Upon Harmonic Representations(int Assoc Engineers-iaeng, 2013) Dinçkal, Çiğdem; Dinckal, Cigdem; İnşaat MühendisliğiThis paper presents a new aspect of harmonic decomposition method for elastic constant tensor of various anisotropic materials. Some misprints found in literature are corrected. This procedure derived here, is applied to anisotropic engineering materials possessing different elastic symmetries. In order to gain insight about these applications, numerical illustrations are presented for anisotropic engineering materials. A new description of norm in terms of harmonic tensors is introduced instead of well-known form of norm. This case is a significant innovation for specifying the anisotropy degree of any engineering materials to have opinion about the mechanical and elastic properties of these materials.Article Citation - Scopus: 2On the Properties of Anisotropic Engineering Materials Based Upon Orthonormal Representations(2012) Dirxçkal, C.; Dinçkal, Çiğdem; İnşaat MühendisliğiA decomposition method[5] based upon orthonormal representations is reviewed and improved toexpress any anisotropic engineering tensor showing the effect of the material properties on the structures. A new decomposed form for the stress tensor (example for symmetric second rank tensor) different from the one available in the literature where the engineering understanding is improved, is presented. Numerical examples from different engineering materials serve to illustrate and verify the decomposition procedure. The norm concept of elastic constant tensor and norm ratios are used to study the anisotropy of these materials. It is shown that this method allows to investigate the elastic and mechanical properties of an anisotropic material possessing any material symmetry and determine anisotropy degree of that material. For a material given from an unknown symmetry, it is possible to determine its material symmetry type by this method.Conference Object Citation - Scopus: 1An Innovative Description of Elastic Constant Tensor Based Upon Orthonormal Representations(Newswood Limited, 2012) Dinçkal, Ç.; Dinçkal, Çiğdem; İnşaat MühendisliğiA new procedure for representation of elastic constant tensor in terms of its orthonormal decomposed parts is presented. Form invariants and orthonormalized basis elements are used to generate this decomposition method. Numerical examples from various engineering materials serve to illustrate and verify the decomposition procedure. The norm concept of elastic constant tensor and norm ratios are used to study the anisotropy of these materials. It is shown that this method allows to investigate the elastic and mechanical properties of an anisotropic material possessing any material symmetry and determine anisotropy degree of that material. For a material given from an unknown symmetry, it is possible to determine its material symmetry type by this method. © 2012 Newswood Limited. All rights reserved.Conference Object Dynamic Stability of Planar Frames Supported by Elastic Foundation(Structural Stability Research Council (SSRC), 2016) Alemdar, B.N.; Dinçkal, Çiğdem; Dinçkal, Ç.; İnşaat MühendisliğiAn exact analytical solution for a vibrating beam-column element on an elastic Winkler foundation is derived. The solution covers all cases comprised of constant compressive and tensile axial force with restrictions of ks -mω1 > 0 and ks -ma>2 < 0. Closed form solutions of dynamic shape functions are explicitly derived for each case and they are used to obtain frequency-dependent dynamic stiffness terms. Governing dynamic equilibrium equations are not only enforced at element ends, but also at any point along the element. To this end, derived stiffness terms are exact and they include distributed mass effects and geometric nonlinear effects such as axial-bending coupling. For this reason, the proposed solution eliminates the need of further element discretization to obtain more accurate results. In absence of elastic foundation (i.e., ks → 0), exact dynamic stiffness terms for beam-columns are also derived and presented in this study. Derived stiffness terms are implemented in a software program and several examples are provided to demonstrate the potential of the present study.Conference Object Citation - WoS: 1Citation - Scopus: 4Orthonormal Decomposition of Third Rank Tensors and Applications(int Assoc Engineers-iaeng, 2013) Dinckal, Cigdem; Dinçkal, Çiğdem; İnşaat MühendisliğiA new procedure for representation of third rank tensors in terms of its orthonormal irreducible decomposed parts, namely as irreducible decomposition is presented. Orthonormal tensor basis method is developed by using the results of existing theory in the literature. As an example to third rank tensors, piezoelectricity tensor is decomposed by each method and results of this decomposition methods are compared for this tensor in hexagonal symmetry. As a result of comparison process, it is stated that the results for new method and other one are consistent and each decomposed parts have physical meaning. Moreover, the norm concept of piezoelectricity tensor is used to study the piezoelectric effect of some materials. It is also shown that one can determine in which material the piezoelectric effect is stronger by using the norm for different materials with the same symmetries.Book Part Design of a Versatile and Rapid Calculator for Oncological Computations(Nova Science Publishers, Inc., 2019) Dinçkal, Ç.; Dinçkal, Çiğdem; İnşaat MühendisliğiIn oncology, there exists many complicated and time-consuming computations for students, clinicians and medical researchers. Although many programs generated in Microsoft Excel have been studied many times, the improvements in design of programs are still an issue of concern. So design of calculator becomes essential for practical use. The objective of this study is to design a rapid and versatile calculator named as TGTSCalculator in Microsoft Excel for comprehensive computation of clonogenic cells amount when growth and irradiation for tumor occurred for all tumor growth models and the total amount of relative cells outliving the treatment schedule (in other words; survival fraction) after radiotherapy. Microsoft Excel with Visual Basics for Applications (VBA) has been employed since it is a high versatile and extensively used special spreadsheet program and easily accessible and available for biomedical scientists and clinicians for a wide range of applications. TGTSCalculator is so transparent and practical that any kind of users requires only requires clicking its macro or CALCULATE button in spreadsheet to manage the all computations effectively and simultaneously. © 2020 by Nova Science Publishers, Inc. All rights reserved.Article Orthonormal decomposition of symmetric second rank tensors(2010) Dinçkal, ÇiğdemIn this paper, a new orthonormal decomposition method for symmetric second rank tensors namely as, orthonormal tensor basis is presented. Complex variable representation method is developed by using the existing theories in literature. For comparison purposes, a brief review of the spectral method is given. It is shown that stress tensor, as an example to symmetric second rank tensors, is decomposed into six orthonormal parts by orthonormal tensor basis and complex variable representation methods. The matrix forms of these decomposed parts are given. This is the first time in literature that physical meanings of each six decomposed parts which are obtained from the orthonormal decomposition of stress tensor by orthonormal tensor basis and complex variable representation methods, different from the traditionally form, are emphasized. Illustrative applications on orthonormal tensor basis and complex variable representation decomposition methods are given. Finally, it is proved that the spectral method is a non-linear decomposition method which yields three non-linear orthonormal decomposed parts. This case is a significant innovation in decomposition procedures for symmetric second rank tensors in literature.Article Norm, norm ratio calculations and anisotropy degree(2011) Dinçkal, ÇiğdemIn this paper, for elastic constant tensor, the norm concept, norm ratio and anisotropy degree are described. The norm of a tensor is used as a criterion for comparing the overall effect of the properties of anisotropic materials and norm ratios are used as a criterion to represent the anisotropy degree of the properties of these materials. Norm and norm ratios as well as the measure of "nearness" to the nearest isotropic tensor are computed for several examples from various anisotropic materials possessing elastic symmetries such as cubic, transversely isotropic, tetragonal, trigonal and orthorhombic. These computations are used to compare and assess the anisotropy in various anisotropic materials by means of strength or magnitude and also determine the "nearness" of the nearest isotropic tensor for the materials with lower symmetry types.Article Studies on the Optimum Mechanical Response of Anısotropıc Materials Related to Elastıc Constants(2011) Dinçkal, ÇiğdemIn this paper, mechanical and elastic behaviour of anisotropic materials are investigated in order to understand the optimum mechanical behaviour of them in selected directions. For an anisotropic material with known elastic constants, it is possible to choose the best set of elastic constants (effective elastic constants) which determine the optimum mechanical and elastic properties of it. For this reason, bounds on the anisotropic elastic constants have been constructed symbollicaly for all anisotropic elastic symmetries. As illustrative examples, materials from different symmetries are selected and their elastic constants are used to compute bounds on the anisotropic elastic constants. Finally, by examining numerical results of bounds given in tables, it is seen that the materials selected from the same symmetry type which have larger interval between the bounds, are more anisotropic, whereas some materials which have smaller interval between the bounds, are closer to isotropy. The construction of bounds on anisotropic elastic constants is a significant and critical case in design of any engineering and structural materials.Article Analysis of Elastic Anisotropy of Wood Material for Engineering Applications(2011) Dinçkal, ÇiğdemThis paper presents a convenient method to describe the degree of the elastic anisotropy in a given type of wood and then discusses its practical values. Besides mechanical and elastic behaviour of wood are investigated in order to understand the optimum mechanical behaviour of it in selected directions. Bounds on the wood elastic constants have been constructed in terms of elasticity and compliance tensors for any type of woods by developing Hill (1952) approach. So for any type of wood with known elastic constants, it is possible to choose the best set of elastic constants (effective elastic constants) which determine the optimum mechanical and elastic properties of it. Bounds on the wood elastic constants as well as the degree of elastic anisotropy are significant and critical cases in design of any engineering and structural materials made up of wood.