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Scopus İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395

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Subject: search.filters.subject.Finite Element MethodWoS Q: search.filters.wosQuartile.N/A

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Now showing 1 - 6 of 6
  • Conference Object
    Evaluation of the Performance of Geotextiles Using Finite Element Analysis in the Settlement Results: A Case Study in Kayseri, Turkey
    (Korean Geosynthetics Society, 2018) Yalçın, Hakan; Akin, Muge K.; Çabalar, Ali Firat
    Geotextiles are successfully designated for the reinforcement of soils to solve certain settlement as well as bearing capacity problems in difficult ground conditions. Furthermore, geotextiles are used for the stability of man-made slopes. In this study, the performance of geotextiles for soil improvement is evaluated by considering various geotextile types that have different axial stiffness values. The stiffness values are compared using a finite element method (FEM) based software PLAXIS 2D. As case study, Kayseri Organized Industrial Site in Turkey was chosen for the comparison of these geotextiles for a specific soil profile during analyses. Besides, the FEM based approach is also considered for the settlement, axial force and the effective stress changes during the application of geotextiles. The selected geotextiles are also correlated using scanning electron microscope (SEM) analyses. The results indicated that the axial stiffness (EA) can be considered with the effect on the possible soil settlement and axial force values. The settlement values reduced with increase in stiffness of reinforcement. © 2021 Elsevier B.V., All rights reserved.
  • Conference Object
    Citation - Scopus: 7
    Design of Capacitive Micromachined Ultrasonic Transducers (Cmuts) on a Flexible Substrate for Intravascular Ultrasonography (Ivus) Applications
    (Institute of Electrical and Electronics Engineers Inc., 2017-05) Hah, Dooyoung; Je, Changhan; Lee, Sung Q.
    Effects of substrate bending to the characteristics of capacitive miniaturized ultrasonic transducers (CMUTs) on a flexible substrate are studied through finite element analysis (FEA) for the design purpose. The target application of the devices is intravascular ultrasonography (IVUS) where transducers are brought to the proximity of the imaging targets so that high resolution images can be obtained without much concern of signal attenuation. In order to eliminate mechanical rotation used in the conventional IVUS, the transducer array can be manufactured on a flexible substrate and to wrap it around a cylindrical frame. It can be anticipated that the characteristics of the transducers will be altered by such bending of the substrate through geometrical dimension changes and stress induced. Pull-in voltages and resonant frequencies of CMUTs were studied via FEA for various bending radii and membrane thicknesses. It was found that both pull-in voltages and resonant frequencies become smaller for the transducers on a bent substrate compared to the ones on a flat substrate. It was also found that pull-in voltages decrease as the substrate bending radius is reduced. © 2017 Elsevier B.V., All rights reserved.
  • Article
    Citation - Scopus: 2
    Deformation Behavior of Nanostructured Aluminum: Experiment and Computational Study
    (Elsevier Ltd, 2023-04) Deka, Surja; Mozafari, Farzin; Mallick, Ashis K.
    Nanocrystalline metals have been processed from powder predecessors in recent times in significant ways, and nowadays, materials are starting to be manufactured which are not only strong but also ductile. Nanocrystalline aluminum (Average grain size 51 nm) was synthesized through high-energy ball milling at the room temperature of microcrystalline powder. The particle size and crystallite sizes were obtained by Williamson Hall and found to be in good correlation with transmission spectroscopy (TEM) data. There was a significant increase in the mechanical properties of nanostructured aluminum in comparison to coarse-grained aluminum. Moreover, a phenomenological model of large-deformation, isotropic, rate-dependent plasticity is developed, which takes into account pressure dependency, plastic dilatation, and non-normal flow. The model has been incorporated into a finite element program. Compression and tension experiments were performed on nanocrystalline aluminum, and the constitutive parameters within the model were estimated from these experiments. The present study shows that the constitutive model successfully simulates the mechanical response of nanocrystalline aluminum with reasonable accuracy using our numerical finite-element capability. © 2023 Elsevier B.V., All rights reserved.
  • Conference Object
    An Fem Study of Die Attach Packaging Effect on Nanomechanical Si Optical Filters
    (Institute of Electrical and Electronics Engineers Inc., 2017-05) Seok, Seonho; Hah, Dooyoung
    This paper presents a finite element analysis of die attach packaging stress effect on emerging nanomechanical silicon optical filters. The proposed silicon optical filter is composed of Si waveguides and a microring resonator having a few hundred nm in thickness and a few tens of μm in length. Photonic integrated circuit is typically implemented by attaching a new component to a common ceramic interposer with other components. Such an attachment process would be a cause of unwanted performance deviation of MEMS or NEMS devices due to the packaging stress. Therefore, an FEM model has been used to evaluate deflection and stress of NEMS waveguides and microring resonators which are main elements for the proposed optical filter. © 2017 Elsevier B.V., All rights reserved.
  • Article
    Citation - Scopus: 32
    Numerical Solutions of the Kawahara Equation by the Septic B-Spline Collocation Method
    (International Academic Press, 2014) Karakoç, Seydi Battal Gazi; Zeybek, Halil; Ak, Turgut; Karakoç, Battal Gazi
    In this article, a numerical solution of the Kawahara equation is presented by septic B-spline collocation method. Applying the Von-Neumann stability analysis, the present method is shown to be unconditionally stable. The accuracy of the proposed method is checked by two test problems. L<inf>2</inf> and L<inf>∞</inf> error norms and conserved quantities are given at selected times. The obtained results are found in good agreement with the some recent results. © 2016 Elsevier B.V., All rights reserved.
  • Article
    Citation - Scopus: 25
    A Cubic B-Spline Galerkin Approach for the Numerical Simulation of the GEW Equation
    (International Academic Press, 2016) Karakoç, Seydi Battal Gazi; Zeybek, Halil; Battal Gazi Karakoç, S.
    The generalized equal width (GEW) wave equation is solved numerically by using lumped Galerkin approach with cubic B-spline functions. The proposed numerical scheme is tested by applying two test problems including single solitary wave and interaction of two solitary waves. In order to determine the performance of the algorithm, the error norms L<inf>2</inf> and L<inf>∞</inf> and the invariants I<inf>1</inf>, I<inf>2</inf> and I<inf>3</inf> are calculated. For the linear stability analysis of the numerical algorithm, von Neumann approach is used. As a result, the obtained findings show that the presented numerical scheme is preferable to some recent numerical methods. © 2016 Elsevier B.V., All rights reserved.