Arama Sonuçları

Listeleniyor 1 - 10 / 13
  • Yayın
    “International conference on vibration problems” ICOVP-2007 and a short history
    (Springer Science and Business Media, LLC, 2008) İnan, Esin
    [No abstract available]
  • Yayın
    Preface
    (Springer Science and Business Media Deutschland GmbH, 2021) Dutta, Subashisa; İnan, Esin; Dwivedy, Santosha Kumar
    [No abstract available]
  • Yayın
    3-D Vibration analysis of microstretch plates
    (Springer, 2008) İnan, Esin; Kiriş, Ahmet
    In the present work, rectangular plates with various boundary conditions are Studied, which are modeled by the rnicrostretch theory. Wave propagation problem is investigated and new waves are observed which do not appear in the classical theory of elasticity. Ritz method is used for this investigation. Triplicate Chebyshev series, multiplied by boundary functions, are used as admissible functions and the frequency equations of the micro-stretch plate are obtained by the use of Chebyshev-Ritz method. The additional frequencies due to the microstructure of the plate are observed among the values of the frequencies obtained from the classical theory of elasticity. We observed that these additional frequencies disappear while the all microstretch constants are taken as zero.
  • Yayın
    Identification of the material properties of microisotropic materials
    (Springer Heidelberg, 2015-07) Kiriş, Ahmet; İnan, Esin
    The vibration problem of a rectangular plate is considered in the present work. The main purpose here is to identify the upper bounds of the unknown material moduli of the microisotropic plate material. The frequency spectrum is obtained by extending Ritz Method to the present case. Three dimensional (3-D) vibration analysis is performed and some additional frequencies are observed among the classical frequencies as characterizing the microisotropic effects. These additional frequencies disappear by increasing values of microisotropic constants beyond some certain limits while the classical frequencies remain in the spectrum. The inverse problem is established for the identification of the upper bounds of the microisotropic constants as an optimization problem where an error function is minimized.
  • Yayın
    Eshelby tensors for a spherical inclusion in microstretch elastic fields
    (Elsevier Ltd, 2006-08) Kırış, Ahmet; İnan, Esin
    In the present work, microelastic and macroelastic fields are presented for the case of spherical inclusions embedded in an infinite microstretch material using the concept of Green's functions. The Eshelby tensors are obtained for a spherical inclusion and it is shown that their forms for microelongated, micropolar and the classical cases are the proper limiting cases of the Eshelby tensors of microstretch materials.
  • Yayın
    Thermo-microstretch elastic bodies and plane waves
    (IOP PUBLISHING LTD, 2011) İnan, Esin; Kırış, Ahmet
    In the present work, vibration problems of rectangular plates are considered for the determination of upper bounds to the unknown microstretch material properties. The frequencies are obtained by extending the Ritz method to this case. The analysis shows that some additional frequencies characterizing the microstretch effects appear among the classical frequencies. Furthermore, by the increasing values of the microstretch constants, the additional frequencies disappear and only the classical frequencies remain in the spectrum. Considering this phenomenon, an optimization problem is established for the identification of the upper bounds of microstretch elastic constants. In the second part of the work, thermal effects are considered and several theories are discussed. Finally, propagation of the plane waves is investigated.
  • Yayın
    On the identification of microstretch elastic moduli of materials by using vibration data of plates
    (Pergamon-Elsevier Science LTD, 2008-06) Kırış, Ahmet; İnan, Esin
    In the present work, the vibration problems of rectangular plates modeled by Eringen's microstretch theory are investigated for the identification of the upper bounds of the microstretch moduli of the plate material. The calculated frequencies of the plates are obtained by extending the Ritz method to the microstretch plates. The three dimensional (3D) vibration analysis of the plates shows that some additional frequencies occur among the classical frequencies as characterizing the microstretch effects. Then it is also observed that these additional frequencies disappear and only the classical frequencies remain with the increasing values of microstretch constants. The inverse problem is established for the identification of the upper bounds of the microstretch elastic constants as an optimization problem where an error function is minimized.
  • Yayın
    Estimation of microstretch elastic moduli by the use of vibrational data
    (Springer, 2007) Kırış, Ahmet; İnan, Esin
    In the present work, a nonlinear wave theory is used for the estimation of the material properties of a "microstretch" medium. For this purpose a thin plate is considered and triplicate Chebyshev polynomial series are used as admissible functions to ensure the satisfaction of geometric boundary conditions of the plate. The Ritz technique is applied to derive the frequency equation of the microstretch plate and an optimization procedure is performed by minimising the least square "distance" between computed natural frequencies from the energy method and measured natural frequencies. To realize the optimization procedure, a genetic algorithm is used to estimate the elastic moduli of microstretch medium.
  • Yayın
    3-D Vibration analysis of the rectangular micro damaged plates
    (Springer, 2008) Kiriş, Ahmet; İnan, Esin
    In the present work, damaged plates are modeled by the micro-elongation theory which neglects the micropolar effects in Eringen's microstretch theory. The wave propagation problem is Studied and a new wave which does not appear in the classical theory of elasticity is observed. The Ritz method is extended to the microelongation theory and triplicate Chebyshev series multiplied by a boundary function are used as admissible functions to approximate plate deflection, and the frequency equations of the microelongated plate are obtained by using Chebyshev-Ritz method. The additional frequencies due to the microstructure of the plate are observed among the values of the classical frequencies. We examined the relation between these additional frequencies and the material constants of the microelongated medium and observed that these additional frequencies disappear while the all microelongational constants are taken as zero.
  • Yayın
    Preface
    (Springer Science and Business Media Deutschland GmbH, 2020) Dutta, Subashisa; İnan, Esin; Dwivedy, Santosha Kumar
    [No abstract available]