İnşaat Mühendisliği Bölümü Yayın Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/395

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  • Conference Object
    Performance-Based Seismic Evaluation and Retrofitting of Historic Unreinforced Concrete Wall Buildings With Interior Steel Frames
    (Dolnoslaskie Wydawnictwo Edukacyjne-dwe, 2012) Gunes, Oguz; Güneş, Oğuz; Gunes, Burcu; Sozenoglu, Ismet; İnşaat Mühendisliği
    Performance-based seismic evaluation of historical constructions is a challenge due to the difficulty of their structural analysis that accurately captures their nonlinear behavior. This paper focuses on the use of 3-D nonlinear finite element method for static pushover analysis of unreinforced concrete (URC) wall buildings with interior steel frames for seismic evaluation and retrofit design. Three such historical school buildings with different levels of structural complexity were modeled in detail using advanced finite element programs to obtain their linear and nonlinear behavior under monotonically increasing lateral loads. The capacity curves obtained from pushover analyses were used for performance evaluation using the Capacity Spectrum Method. Retrofit design verification for one of the buildings was performed using the same approach. The results show that despite its involved modeling process and computational expense, pushover analysis of buildings with URC/URM elements using 3-D nonlinear finite element method can become a powerful practical tool for improved seismic performance evaluation and retrofit design.
  • 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 Mühendisliği
    This 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: 2
    On the Properties of Anisotropic Engineering Materials Based Upon Orthonormal Representations
    (2012) Dirxçkal, C.; Dinçkal, Çiğdem; İnşaat Mühendisliği
    A 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.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 4
    An Analytical Investigation of Rigid Plastic Beams Under Impact Loading
    (Gazi Univ, Fac Engineering Architecture, 2015) Gultop, Tekin; Gültop, Tekin; Yilmaz, Mahmut Cem; Alyavuz, Bahadir; İnşaat Mühendisliği
    Beams might be subjected to impact loading which is a particular type of dynamic loading during their service lives. In this study the behaviour of beams under low speed impact loading has been investigated analytically. Simply supported and fixed ended beams have been analyzed with the assumption of rigid plastic behaviour. The collapse mechanism has been assumed to emerge by the instant formation of plastic hinges, hence, a limit analysis has been performed under dynamic loading considering the conservation principles of energy and momentum. The behaviour of rigid plastic beams under impact loading has been compared to the behaviour of elastic beams under similar loading conditions.
  • Conference Object
    Citation - Scopus: 1
    An Innovative Description of Elastic Constant Tensor Based Upon Orthonormal Representations
    (Newswood Limited, 2012) Dinçkal, Ç.; Dinçkal, Çiğdem; İnşaat Mühendisliği
    A 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 Mühendisliği
    An 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 - Scopus: 2
    Wind Energy Development in Turkey: Policies and Challenges
    (European Wind Energy Association, 2013) Kucukali, S.; Küçükali, Serhat; İnşaat Mühendisliği
    This paper aims to explore the availability and potential of wind energy in Turkey as well as assessing related government policies and challenges. As a European Union (EU) candidate several incentives were developed in Turkey for electricity generation from renewable energy sources by the enactment of Law No. 5346 in 2005 which was later restructured by Law No. 6094 in 2010. By June 2012, 57 wind power plants in operation with a total installed capacity of 1776 MW; whereas there are 212 wind power plants are under construction with a total installed capacity of 7166 MW. Within the scope of the study a survey was conducted with experts in order to determine the main barriers for wind energy development. The survey results revealed that the grid connection and change of laws were considered as the most important risks for wind energy development in Turkey. The findings of the case studies demonstrated that the perception of inadequate understanding of the risks elements can lead to project schedule overrun which can result in significant revenue loss.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 4
    Orthonormal Decomposition of Third Rank Tensors and Applications
    (int Assoc Engineers-iaeng, 2013) Dinckal, Cigdem; Dinçkal, Çiğdem; İnşaat Mühendisliği
    A 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 Mühendisliği
    In 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
    Citation - WoS: 8
    Citation - Scopus: 9
    Damage Limits for Ductile Reinforced Concrete Shear Walls
    (Turkish Chamber Civil Engineers, 2012) Gülkan, Hakkı Polat; Kazaz, Ilker; Gulkan, Polat; İnşaat Mühendisliği
    Although the strain based damage limits proposed in the existing Turkish Earthquake Code were adopted from reported studies of leading researchers, the appropriateness of these limit state definitions and corresponding values to evaluate the performance with the analytical tools and methods used in the displacement based design and assessment procedures has not been verified properly. The moment-curvature analysis based on the plane section hypothesis is severely violated especially for reinforced concrete walls. This indicates that a comprehensive investigation is required to investigate the validity of proposed damage limits for structural walls. This study is based on advanced and computationally rigorous numerical procedures to investigate the relation between drift ratio, plastic rotation and curvature, compressive strain in concrete and tensile strain in steel for rectangular reinforced concrete structural walls. Validity of the requirements related to deformation limits in the Turkish Seismic Code and other design guidelines is then evaluated. Modeling and acceptance criteria that are more accurate than the existing ones have been proposed for structural walls.