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Mustafa Özgür Yayli - One of the best experts on this subject based on the ideXlab platform.

  • buckling analysis of euler columns embedded in an elastic medium with general elastic boundary conditions
    Mechanics Based Design of Structures and Machines, 2018
    Co-Authors: Mustafa Özgür Yayli
    Abstract:

    ABSTRACTIn this article, an efficient analytical method for elastically restrained Euler columns embedded in an elastic medium has been proposed to calculate buckling loads. The lateral deflection function under compression is represented by a Fourier Sine Series. Stokes’ transformation is employed to develop the legitimized stability equations. Explicit analytical expressions are derived, which can be used for any type of boundary conditions. The efficiency of present formulation is demonstrated by comparing the results to those obtained by imposing three well-known boundary conditions available in the literature. A very good agreement has been obtained. The present formulation permits to have more efficient coefficient matrix for calculating the buckling loads of Euler columns with any desired boundary conditions.

  • Buckling analysis of a cantilever single-walled carbon nanotube embedded in an elastic medium with an attached spring
    Micro & Nano Letters, 2017
    Co-Authors: Mustafa Özgür Yayli
    Abstract:

    The buckling analysis of a cantilever single-walled carbon nanotube embedded in an elastic medium with an attached spring is researched. The effects of axial compression load, attached spring, small size and surrounding elastic medium are taken into account at the same time. Theoretical formulation is carried out on the basis of the Bernoulli-Euler beam theory in conjunction with Eringen's non-local elasticity theory. Fourier Sine Series is selected for the simulation of single-walled carbon nanotube deflections. Winkler elastic foundation type is used to simulate the interaction between single-walled carbon nanotube and elastic medium. 2 × 2 coefficient matrix is derived with the aid of applying Stokes' transformation to corresponding non-local boundary conditions. The critical buckling loads are calculated by using this coefficient matrix. Different validation studies are performed to endorse and corroborate the usefulness of the presented analytical method.

  • Buckling Analysis of Non-Local Timoshenko Beams by Using Fourier Series
    Akdeniz University, 2017
    Co-Authors: Hayrullah Kadıoğlu, Mustafa Özgür Yayli
    Abstract:

    In this study, buckling analysis of a nano sized beam has been performed by using Timoshenko beam theory and Eringen’s nonlocal elasticity theory. Timoshenko beam theory takes into account not only bending moment but also shear force. Therefore, it gives more accurate outcomes than Euler Bernoulli beam theory. Moreover, Eringen’s nonlocal elasticity theory takes into account the small scale effect. Thus, these two theories are utilized in this study. The vertical displacement function is chosen as a Fourier Sine Series. Similarly, the rotation function is chosen as a Fourier coSine Series. These functions are enforced by Stokes’ transformation, and higher order derivatives of them are obtained. These derivatives are written in the governing equations for the buckling of nonlocal Timoshenko beams. Hence Fourier coefficients are acquired. Subsequently boundary condition of established beam model is identified with Timoshenko beam and Eringen’s nonlocal elasticity theories, and the linear equations are obtained. A coefficients matrix is created by utilizing these linear systems of equations. When determinant of this coefficient matrix is calculated, the critical buckling loads are acquired. Finally, achieved outcomes are compared with other studies in the literature. Calculated results are also presented in a Series of figures and table

  • an analytical solution for free vibrations of a cantilever nanobeam with a spring mass system
    International Journal of Engineering and Applied Sciences, 2016
    Co-Authors: Mustafa Özgür Yayli
    Abstract:

    An analytical solution for the title problem is presented using the nonlocal elasticity theory based on Euler-Bernoulli beam theory. Fourier Sine Series is used to represent lateral displacement of the nanobeam. Stokes’ transformation is applied to derive the coefficient matrix of the corresponding systems of linear equations. This matrix also contains the relationship between spring and mass parameters. A convergence study is provided to show how the first three frequency parameter of the nanobeam would converge by an increase of Series terms in the literature. The results are given in a Series of figures and tables for various combinations of boundary conditions

  • A practical method for calculating eigenfrequencies of a cantilever microbeam with the attached tip mass
    'JVE International Ltd.', 2016
    Co-Authors: Mustafa Özgür Yayli, Süheyla Yerel Kandemir, Ali Erdem Çerçevik
    Abstract:

    This paper is concerned with the free vibration of cantilever microbeams with attached tip mass in a systematical manner. Small size effects on the vibrations of the microbeam are taken into consideration by introducing a scale parameter. A Fourier Sine Series is used to represent the lateral displacement function. Stokes’ transformation is applied in the present formulation and corresponding derivatives are presented explicitly. The present formulations can be readily reduced to those for others classical elasticity models by setting corresponding small scale parameter to zero. Several parametric studies are performed to validate the present solutions and the effects of various important physical parameters (scale parameter, tip mass) are investigated

Toklu Y. Cengiz - One of the best experts on this subject based on the ideXlab platform.

  • Dönmeye Karşı Kontrol Altına Alınmış Basit Mesnetli Çubukların Stoke Dönüşümü Yardımıyla Burkulma Analizi
    Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2017
    Co-Authors: Yaylı M. Özgür, Çerçevik A. Erdem, Toklu Y. Cengiz
    Abstract:

    Bu çalışmada eksenel yüklenmiş basit mesnetli bir kirişin burkulma yüklerinin tespiti için yerel bir analitik yöntem geliştirilmiştir. Ayrıca kiriş uçlarından dönmeye karşı engelleyici yaylar ile sabitlenmiştir. Çalışmada Euler-Bernoulli kiriş teorisi kullanılmıştır. İlk olarak literatürde çok iyi bilinen Euler-Bernoulli kiriş teorisinin denklemi eksenel yükler altında verilmiştir. Analitik genel çözümlerin elde edilmesi için yer değiştirme fonksiyonu Fourier sinüs serisi seçilmiştir. Fourier sinüs serisinin seçilmesinin kirişin basit mesnetli olması ile bir ilgisi bulunmamaktadır. Literatürdeki çalışmalarda basit mesnetli kirişlerin sınır koşullarını sağladığı için genellikle Fourier sinus serileri kullanılmaktadır. Mesnetlerde dönmeye karşı yaylar kullanıldığı için; sınır koşullarında serbestlik sağlaması bakımından Stoke dönüşümü uygulanmıştır. Bu dönüşümün yapılmasının temel amacı yay sabitlerine verilecek değerlerde esneklik sağlamasıdır.This paper presents an analytical method for buckling analysis of simply supported beam with rotational restraints at both ends. Euler Bernoulli theory is used. The lateral displacement function is sellected by a Fourier Sine Series. Stokes’ transformation is applied to boundary conditions in order to construct the coefficient matrix. This application gives more flexibility for buckling analysis of beams with different boundary conditions. Comparisons are performed to validate present analytical method

  • Dönmeye Karşı Kontrol Altına Alınmış Basit Mesnetli Çubukların Stoke Dönüşümü Yardımıyla Burkulma Analizi
    Theoretical and Applied Mechanical Turkish National Committee, 2015
    Co-Authors: Yaylı M. Özgür, Çerçevik A. Erdem, Toklu Y. Cengiz
    Abstract:

    Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada eksenel yüklenmiş basit mesnetli bir kirişin burkulma yüklerinin tespiti için yerel bir analitik yöntem geliştirilmiştir. Ayrıca kiriş uçlarından dönmeye karşı engelleyici yaylar ile sabitlenmiştir. Çalışmada Euler-Bernoulli kiriş teorisi kullanılmıştır. İlk olarak literatürde çok iyi bilinen Euler-Bernoulli kiriş teorisinin denklemi eksenel yükler altında verilmiştir. Analitik genel çözümlerin elde edilmesi için yer değiştirme fonksiyonu Fourier sinüs serisi seçilmiştir. Fourier sinüs serisinin seçilmesinin kirişin basit mesnetli olması ile bir ilgisi bulunmamaktadır. Literatürdeki çalışmalarda basit mesnetli kirişlerin sınır koşullarını sağladığı için genellikle Fourier sinus serileri kullanılmaktadır. Mesnetlerde dönmeye karşı yaylar kullanıldığı için; sınır koşullarında serbestlik sağlaması bakımından Stoke dönüşümü uygulanmıştır. Bu dönüşümün yapılmasının temel amacı yay sabitlerine verilecek değerlerde esneklik sağlamasıdır.This paper presents an analytical method for buckling analysis of simply supported beam with rotational restraints at both ends. Euler Bernoulli theory is used. The lateral displacement function is sellected by a Fourier Sine Series. Stokes’ transformation is applied to boundary conditions in order to construct the coefficient matrix. This application gives more flexibility for buckling analysis of beams with different boundary conditions. Comparisons are performed to validate present analytical method

Lei Wang - One of the best experts on this subject based on the ideXlab platform.

  • semi analytical solutions to the two dimensional plane strain consolidation for unsaturated soil with the lateral semi permeable drainage boundary under time dependent loading
    Computers and Geotechnics, 2020
    Co-Authors: Lei Wang, Xiaohe Xia, Annan Zhou
    Abstract:

    Abstract Using Fourier Sine Series expansion and Laplace transform, semi-analytical solutions for the two-dimensional plane strain consolidation problem of unsaturated soils are presented subjected to time-dependent loading with the lateral semi-permeable drainage boundary (LSDB), which is the third boundary and can be used to consider the smear effect of the vertical drain. Then, degenerated and numerical solutions are provided to verify the validity of the proposed solutions. Finally, the consolidation property involving the LSDB and time-dependent loading is depicted and analyzed, and the consolidation behavior is shown to result from the application of the LSDB and loading.

  • semi analytical solutions to two dimensional plane strain consolidation for unsaturated soils under time dependent loading
    Computers and Geotechnics, 2019
    Co-Authors: Lei Wang, Xiaohe Xia
    Abstract:

    Abstract This paper presents semi-analytical solutions of two-dimensional plane strain consolidation for unsaturated soils under time-dependent loading using Fourier Sine Series and Laplace transform. The consolidation equations in form of two-order partial differential equations with three variables are firstly converted to that with two variables. Then four-order ordinary differential equations about excess pore-air and pore-water pressures are presented, and the semi-analytical solutions of excess pore-air and pore-water pressures and settlement are achieved in the Laplace transform domain. Two comparisons are performed to verify the exactness of the obtained solutions, and the consolidation behavior involving three time-dependent loadings is illustrated and discussed.

Robert C Schwartz - One of the best experts on this subject based on the ideXlab platform.

  • soil profile method for soil thermal diffusivity conductivity and heat flux comparison to soil heat flux plates
    Advances in Water Resources, 2012
    Co-Authors: Steven R Evett, Nurit Agam, William P Kustas, Paul D Colaizzi, Robert C Schwartz
    Abstract:

    Abstract Diffusive heat flux at the soil surface is commonly determined as a mean value over a time period using heat flux plates buried at some depth (e.g., 5–8 cm) below the surface with a correction to surface flux based on the change in heat storage during the corresponding time period in the soil layer above the plates. The change in heat storage is based on the soil temperature change in the layer over the time period and an estimate of the soil thermal heat capacity that is based on soil water content, bulk density and organic matter content. One- or multiple-layer corrections using some measure of mean soil temperature over the layer depth are common; and in some cases the soil water content has been determined, although rarely. Several problems with the heat flux plate method limit the accuracy of soil heat flux values. An alternative method is presented and this flux gradient method is compared with soil heat flux plate measurements. The method is based on periodic (e.g., half-hourly) water content and temperature sensing at multiple depths within the soil profile and a solution of the Fourier heat flux equation. A Fourier Sine Series is fit to the temperature at each depth and the temperature at the next depth below is simulated with a Sine Series solution of the differential heat flux equation using successive approximation of the best fit based on changing the thermal diffusivity value. The best fit thermal diffusivity value is converted to a thermal conductivity value using the soil heat capacity, which is based on the measured water content and bulk density. A statistical analysis of the many data resulting from repeated application of this method is applied to describe the thermal conductivity as a function of water content and bulk density. The soil heat flux between each pair of temperature measurement depths is computed using the thermal conductivity function and measured water contents. The thermal gradient method of heat flux calculation compared well to values determined using heat flux plates and calorimetric correction to the soil surface; and it provided better representation of the surface spatiotemporal variation of heat flux and more accurate heat flux values. The overall method resulted in additional important knowledge including the water content dynamics in the near-surface soil profile and a soil-specific function relating thermal conductivity to soil water content and bulk density.

Yaylı M. Özgür - One of the best experts on this subject based on the ideXlab platform.

  • Dönmeye Karşı Kontrol Altına Alınmış Basit Mesnetli Çubukların Stoke Dönüşümü Yardımıyla Burkulma Analizi
    Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2017
    Co-Authors: Yaylı M. Özgür, Çerçevik A. Erdem, Toklu Y. Cengiz
    Abstract:

    Bu çalışmada eksenel yüklenmiş basit mesnetli bir kirişin burkulma yüklerinin tespiti için yerel bir analitik yöntem geliştirilmiştir. Ayrıca kiriş uçlarından dönmeye karşı engelleyici yaylar ile sabitlenmiştir. Çalışmada Euler-Bernoulli kiriş teorisi kullanılmıştır. İlk olarak literatürde çok iyi bilinen Euler-Bernoulli kiriş teorisinin denklemi eksenel yükler altında verilmiştir. Analitik genel çözümlerin elde edilmesi için yer değiştirme fonksiyonu Fourier sinüs serisi seçilmiştir. Fourier sinüs serisinin seçilmesinin kirişin basit mesnetli olması ile bir ilgisi bulunmamaktadır. Literatürdeki çalışmalarda basit mesnetli kirişlerin sınır koşullarını sağladığı için genellikle Fourier sinus serileri kullanılmaktadır. Mesnetlerde dönmeye karşı yaylar kullanıldığı için; sınır koşullarında serbestlik sağlaması bakımından Stoke dönüşümü uygulanmıştır. Bu dönüşümün yapılmasının temel amacı yay sabitlerine verilecek değerlerde esneklik sağlamasıdır.This paper presents an analytical method for buckling analysis of simply supported beam with rotational restraints at both ends. Euler Bernoulli theory is used. The lateral displacement function is sellected by a Fourier Sine Series. Stokes’ transformation is applied to boundary conditions in order to construct the coefficient matrix. This application gives more flexibility for buckling analysis of beams with different boundary conditions. Comparisons are performed to validate present analytical method

  • Dönmeye Karşı Kontrol Altına Alınmış Basit Mesnetli Çubukların Stoke Dönüşümü Yardımıyla Burkulma Analizi
    Theoretical and Applied Mechanical Turkish National Committee, 2015
    Co-Authors: Yaylı M. Özgür, Çerçevik A. Erdem, Toklu Y. Cengiz
    Abstract:

    Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada eksenel yüklenmiş basit mesnetli bir kirişin burkulma yüklerinin tespiti için yerel bir analitik yöntem geliştirilmiştir. Ayrıca kiriş uçlarından dönmeye karşı engelleyici yaylar ile sabitlenmiştir. Çalışmada Euler-Bernoulli kiriş teorisi kullanılmıştır. İlk olarak literatürde çok iyi bilinen Euler-Bernoulli kiriş teorisinin denklemi eksenel yükler altında verilmiştir. Analitik genel çözümlerin elde edilmesi için yer değiştirme fonksiyonu Fourier sinüs serisi seçilmiştir. Fourier sinüs serisinin seçilmesinin kirişin basit mesnetli olması ile bir ilgisi bulunmamaktadır. Literatürdeki çalışmalarda basit mesnetli kirişlerin sınır koşullarını sağladığı için genellikle Fourier sinus serileri kullanılmaktadır. Mesnetlerde dönmeye karşı yaylar kullanıldığı için; sınır koşullarında serbestlik sağlaması bakımından Stoke dönüşümü uygulanmıştır. Bu dönüşümün yapılmasının temel amacı yay sabitlerine verilecek değerlerde esneklik sağlamasıdır.This paper presents an analytical method for buckling analysis of simply supported beam with rotational restraints at both ends. Euler Bernoulli theory is used. The lateral displacement function is sellected by a Fourier Sine Series. Stokes’ transformation is applied to boundary conditions in order to construct the coefficient matrix. This application gives more flexibility for buckling analysis of beams with different boundary conditions. Comparisons are performed to validate present analytical method