Person: YAYLI, MUSTAFA ÖZGÜR
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YAYLI
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MUSTAFA ÖZGÜR
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Publication Longitudinal vibration analysis of FG nanorod restrained with axial springs using doublet mechanics(Taylor & Francis, 2021-10-26) Civalek, Ömer; Uzun, Büsra; Yaylı, Mustafa Özgür; UZUN, BÜŞRA; YAYLI, MUSTAFA ÖZGÜR; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; 0000-0003-2231-170X; AAJ-6390-2021; ABE-6914-2020In the current paper, the free longitudinal vibration response of axially restrained functionally graded nanorods is presented for the first time based on the doublet mechanics theory. Size dependent nanorod is considered to be made of functionally graded material consist of ceramic and metal constituents. It is assumed that the material properties of the functionally graded nanorod are assumed to vary in the radial direction. The aim of this study is that to investigate the influences of various parameters such as functionally graded index, small size parameter, length of the nanorod, mode number and spring stiffness on vibration behaviors of functionally graded nanorod restrained with axial springs at both ends. For this purpose, Fourier sine series are used to define the axial deflection of the functionally graded nanorod. Then, an eigenvalue approach is established for longitudinal vibrational frequencies thanks to Stokes' transformation to deformable axial springs. Thus, the presented eigenvalue solution method is attributed to both rigid and deformable boundary conditions for the axial vibration of the functionally graded nanorod. With the help of the results obtained with the presented eigenvalue problem, it is observed that the parameters examined cause significant changes in the frequencies of the functionally graded nanorod.Publication Torsional static and free vibration analysis of noncircular short-fiber-reinforced microwires with arbitrary boundary conditions(Wiley, 2023-03-29) Civalek, Ömer; Uzun, Büşra; UZUN, BÜŞRA; Yaylı, Mustafa Özgür; YAYLI, MUSTAFA ÖZGÜR; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-1907-9479; 0000-0002-7636-7170; 0000-0003-2231-170X; AAJ-6390-2021; ABE-6914-2020This study investigates the free torsional vibration response of short fiber-reinforced noncircular microwires by considering the size effect. Moreover, the formulation of Eigen value problem based on forced boundary conditions that consider warping function and small-scale parameter. The composite microwire has been considered to be composed of fiber reinforced by short particle distributed along the thickness direction based on different symmetric patterns. The partial differential equation with force boundary conditions of a microwire under the general boundary conditions are presented in a matrix form and are solved analytically via the modified couple stress theory. An analytical solution is obtained for a microwire with arbitrary boundary conditions using the Fourier sine series with Stokes' transformation and effect of different parameters including warping function and elastic springs at the ends, material length scale parameter, distribution of short fibers on the free torsional frequencies are investigated.Publication Porosity and deformable boundary effects on the dynamic of nonlocal sigmoid and power-law fg nanobeams embedded in the winkler-pasternak medium(Springer Heidelberg, 2023-07-02) UZUN, BÜŞRA; Uzun, Büşra; YAYLI, MUSTAFA ÖZGÜR; Yaylı, Mustafa Özgür; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; ABE-6914-2020ObjectiveThe aim of this study is to solve the free vibrations of embedded functionally graded porous and non-porous nanobeams with different material distributions (power-law and sigmoid) under general elastic boundary conditions to better understand the dynamic properties. This form of model has the benefit of allowing one to handle the rigid or restrained supporting conditions.MethodA solution method using the Fourier sine series and Stokes' transform together is adopted. This method is used to study the effects of deformable boundary conditions as well as rigid boundary conditions, which are common in the literature. In the current study, two sets of equations for both elastic support conditions consisting of infinite series are derived. Then, eigenvalue problems are set up for the analytical solution. The eigenvalues of the established problems give the vibration frequencies of the embedded functionally graded porous/non-porous nanobeams.ConclusionsThe proposed models are effective for studying arbitrary boundary conditions. The accuracy of the model is compared with some results from the literature for rigid boundary conditions. Looking at the frequencies of functionally graded porous/non-porous nanobeams, it is seen that the studied parameters such as foundation parameters, nonlocal parameter, grading index, elastic spring stiffness produce changes that cannot be ignored.Publication Torsional and axial vibration of restrained saturated nanorods via strain gradient elasticity(Springer, 2022-12-31) Civalek, Ömer; Uzun, Büşra; UZUN, BÜŞRA; Yaylı, Mustafa Özgür; YAYLI, MUSTAFA ÖZGÜR; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; 0000-0003-1907-9479; ABE-6914-2020; HKT-5010-2023Size-dependent torsional and longitudinal free vibrations of restrained saturated porous nanorods are studied by a higher-order elasticity theory. The strain gradient elasticity model is used in this study able to overcome inconsistencies of classical elasticity model. The presented higher-order model leads to well-posed boundary value problem for arbitrary value of the small size parameter. Two elastic springs in torsional and axial directions are attached to saturated porous nanorods at two boundary points. Angular rotation and axial deflection functions based on the strain gradient elasticity model are represented by two Fourier sine series. The difference of this proposed solution is that it does not impose a limitation on the support conditions and allows the frequencies to be obtained with a single solution. Two coefficient matrices including torsional or axial effects are obtained by using Stokes' transformation and non-classical boundary conditions. Free vibration frequencies of saturated nanorods are calculated by an effective eigen-value solution strategy. It is shown clearly that elastic spring coefficients, small-scale parameter and saturation a notable impact on the dynamic response of nanorods.Publication Stability analysis of arbitrary restrained nanobeam embedded in an elastic medium via nonlocal strain gradient theory(Sage Publications Ltd, 2023-04-19) Uzun, Büşra; Yaylı, Mustafa Özgür; UZUN, BÜŞRA; YAYLI, MUSTAFA ÖZGÜR; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; 0000-0003-2231-170X; AAJ-6390-2021; ABE-6914-2020A novel stability model is analytically reformulated for the nano-sized beam resting on a one-parameter elastic foundation. The stability solution is based on the nonlocal strain gradient elasticity theory. To corporate the small size effects, two small scale parameters are introduced. The six-order ordinary differential form of the buckling equation, together with two force boundary conditions, are utilized to examine the stability equation in terms of lateral deflection. The infinite terms of linear equations are discretized with the help of the Stokes' transformation and Fourier sine series. The present work can investigate the effects of elastic spring parameters at the ends, nonlocal properties, elastic medium properties, strain gradient parameter, and buckling behavior of the nanobeam. The predictions of the proposed analytical model with deformable boundary conditions are in agreement with those available in the scientific literature for the nanobeam on elastic foundation based on a closed form of solution. The presence of the deformable conditions, elastic foundation, nonlocal, and strain gradient properties change the buckling loads and buckling mode shapes.Publication Nonlocal strain gradient approach for axial vibration analysis of arbitrary restrained nanorod(Springer, 2022-11-01) Uzun, Büşra; Civalek, Ömer; Yaylı, Mustafa Özgür; UZUN, BÜŞRA; YAYLI, MUSTAFA ÖZGÜR; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; AAJ-6390-2021; ABE-6914-2020Axial free vibration analysis of small size-dependent nanorod subjected to deformable restrained boundary conditions is carried out in the present work. Unlike previous works, the formulation is rewritten without resorting to any un-deformable boundary conditions neither clamped ends with Navier approximation nor considering nanorod as a compact form without any discontinuities, and the boundary conditions are assumed to be gradually deformable in the axial direction. Within the framework of Fourier sine series and Stokes' transformation, an eigenvalue problem is constructed to obtain the axial vibration frequencies. In addition, the higher-order elasticity model contains a material scale parameter considering the prominence of strain gradient stress field and a nonlocal coefficient considering the prominence of nonlocal elastic stress field. The validity of the presented procedure is checked by comparing the obtained results by giving proper values to elastic spring parameters, and good agreement is achieved. Numerical results and graphical representation are presented to demonstrate the applicability of the presented eigenvalue solution to examine the free axial response of nanorods with arbitrary boundary conditions. Effects of small-scale parameters on the dynamic response of nanorods are discussed in detail.Publication An effective analytical method for buckling solutions of a restrained fgm nonlocal beam(Springer Heidelberg, 2022-03-01) Civalek, Ömer; UZUN, BÜŞRA; Uzun, Büşra; Yaylı, Mustafa Özgür; YAYLI, MUSTAFA ÖZGÜR; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; 0000-0003-2231-170X; AAJ-6390-2021; ABE-6914-2020This work studies the size-dependent stability analysis of restrained nanobeam with functionally graded material via nonlocal Euler-Bernoulli beam theory using the Fourier series. The nonlocal elasticity theory introduced by Eringen is utilized to show the size effect on the buckling response of restrained functionally graded nanobeam. In addition, buckling loads of functionally graded nanobeam are obtained by classical elasticity theory as well to highlight the size effects. The influences of various parameters such as the nonlocal parameter, rotational restraints and power-law index on the critical buckling load of the functionally graded nonlocal beam are investigated. The contribution of this paper is that it presents an efficient analytical solution for the buckling response of functionally graded nanobeam with non-rigid boundary conditions.Publication A fourier sine series solution of static and dynamic response of nano/micro-scaled fg rod under torsional effect(Techno-press, 2022-05-01) Civalek, Ömer; Yaylı, M. Özgür; YAYLI, MUSTAFA ÖZGÜR; Uzun, Büşra; UZUN, BÜŞRA; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0003-1907-9479; 0000-0002-7636-7170; 0000-0003-2231-170X; ABE-6914-2020; AAJ-6390-2021In the current work, static and free torsional vibration of functionally graded (FG) nanorods are investigated using Fourier sine series. The boundary conditions are described by the two elastic torsional springs at the ends. The distribution of functionally graded material is considered using a power-law rule. The systems of equations of the mechanical response of nanorods subjected to deformable boundary conditions are achieved by using the modified couple stress theory (MCST) and taking the effects of torsional springs into account. The idea of the study is to construct an eigen value problem involving the torsional spring parameters with small scale parameter and functionally graded index. This article investigates the size dependent free torsional vibration based on the MCST of functionally graded nano/micro rods with deformable boundary conditions using a Fourier sine series solution for the first time. The eigen value problem is constructed using the Stokes' transform to deformable boundary conditions and also the convergence and accuracy of the present methodology are discussed in various numerical examples. The small size coefficient influence on the free torsional vibration characteristics is studied from the point of different parameters for both deformable and rigid boundary conditions. It shows that the torsional vibrational response of functionally graded nanorods are effected by geometry, small size effects, boundary conditions and material composition. Furthermore, for all deformable boundary conditions in the event of nano-sized FG nanorods, the incrementing of the small size parameters leads to increas the torsional frequencies.Publication Critical buckling loads of embedded perforated microbeams with arbitrary boundary conditions via an efficient solution method(Walter De Gruyter Gmbh, 2022-11-23) Civalek, Ömer; Yayli, Mustafa Ozgur; YAYLI, MUSTAFA ÖZGÜR; Uzun, Busra; UZUN, BÜŞRA; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; AAJ-6390-2021; ABE-6914-2020In the present work, the small size effects on stability properties of perforated microbeams under various types of deformable boundary conditions are studied considering the Fourier sine series solution procedure and a mathematical procedure known as Stokes' transformation for the first time. The main benefit of the present method is that, in addition to considering both the gradient elasticity and the size effects, the kinematic boundary conditions are modeled by two elastic springs as deformable boundary conditions. The deformable boundary conditions and corresponding stability equation are described using the classical principle which are then used to construct a linear system of equations. Afterward, an eigenvalue problem is adopted to obtain critical buckling loads. The correctness and accuracy of the present model are demonstrated by comparing results with those available from other works in the literature. Moreover, a numerical problem is solved and presented in detail to show the influences of the perforation properties, geometrical, and the variation of small-scale parameters and foundation parameters on the stability behavior of the microbeams. In addition, according to the best knowledge of the authors, there is no study in the literature that examines the buckling behavior of perforated microbeams on elastic foundation with the gradient elasticity theory.Publication Buckling analysis of nanobeams with deformable boundaries via doublet mechanics(Springer, 2021-09-07) Civalek, Ömer; Uzun, Büşra; Yaylı, Mustafa Özgür; UZUN, BÜŞRA; YAYLI, MUSTAFA ÖZGÜR; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; 0000-0002-7636-7170; 0000-0003-2231-170X; AAJ-6390-2021; ABE-6914-2020Buckling analysis of nanobeams with deformable boundary conditions is researched within the framework of doublet mechanics. This theory is an alternative nanomechanics theory for continuum modeling of the granular micromaterials. Doublet mechanics theory takes into consideration the small size parameter due to dealing with also granular nanosized structures. In many studies, rigid supporting conditions are explored in the nanomechanical analysis of beams. Even though the supporting conditions are accepted as undeformable, it is not possible to provide the desired rigidity in practice. A few studies have been conducted to explore the effects of deformable boundaries. In the present work, Fourier sine series as well as Stokes' transformation are utilized to attain the eigenvalue formulation and eigenvector characteristics of the problem. The combination of these two methods is a new approach in applied mechanics; at the same time, it is planned to create a bridge between rigid and deformable boundary conditions. By solving various examples, the accuracy of the proposed method has been tested and an excellent agreement has been achieved with the literature. In addition, the effect of the springs in the boundaries on the critical buckling load has been examined and given in a series of graphs.