Browsing by Author "Dasdemir, A"
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Web of Science Publication A finite element model for a bi-layered piezoelectric plate-strip with initial stresses under a time-harmonic force(2022-08-01) Daşdemir A.; Dasdemir, AThe novelty of this study is presenting the analytical approach to investigate the dynamic response and the forced vibration by a time-harmonic force of a bi-layered piezoelectric plate-strip with initial stresses, resting on a rigid foundation. Material properties are varied perpendicular to the free surface of the plate-strip according to a simple power-law distribution. Firstly, the nonlinear mechanical equations of motion are linearized within the scope of the three-dimensional linearized theory of elastic waves in initially stressed bodies (TLTEWISB). Furthermore, using the piezoelectricity material properties, linear electrical governing equations are derived. Next, the problem under consideration is solved by the finite element method (FEM) to determine, especially the frequency response of the body. The approach is verified by the previous results in the literature. In numerical results, the influences of the initial stress, the height ratio of the layers, thickness ratio, and dimensionless frequency parameters on the dynamic response and the forced vibration of the bi-layered piezoelectric plate-strip are presented and discussed in detail.Web of Science Publication A Modal Analysis of Forced Vibration of a Piezoelectric Plate with Initial Stress by the Finite-Element Simulation(2022-03-01) Daşdemir A.; Dasdemir, AA modal analysis of forced vibrations caused by a time-harmonic force from a piezoelectric plate standing on a rigid foundation is presented. A 3D linearized elasticity theory for solids under initial stress (TLTESIS) is used. It is assumed that a uniformly distributed normal loadings acting on the lateral surfaces of the plate yield the initial stress state. The piezoelectric plate is under the action of a time-harmonic force poled in various directions. A mathematical model is developed, and the problem is solved employing the 3D finite-element method (3D-FEM). Some numerical results illustrating the influence of changes in the poling direction and other important factors, such as the initial stress, on the dynamic behavior of the plate are presented.Web of Science Publication A spring-layer model for a bi-layered plate-strip with initial stress through imperfect contact interface(2019-01-01) Daşdemir A.; Dasdemir, AIn this paper, we present our report on the forced vibration of a bi-layered plate-strip with initial stress resting on a rigid foundation induced by a time-harmonic force. The investigation is carried out according to the piecewise homogeneous body model with utilizing the three-dimensional linearized theory of elastic waves in initially stressed bodies (TLTEWISB). The materials of the body are chosen to be linearly elastic, homogeneous, and isotropic. The interface between the layers is assumed to be imperfect, and is simulated by the spring-layer model. A similar degree of imperfection on the interface is realized in the normal and tangential directions. The mathematical model for the problem under consideration is designed, and the system of the equations of motion is approximately solved by employing the finite element method (FEM). The numerical results explaining the influence of the parameter that characterizes the degree of corresponding imperfectness on the dynamic response of the plate-strip are presented. In particular, we demonstrate that the distributions of the normal stress become flat, as the normal-spring parameter increases.Web of Science A Study on Horadam Hybrid Numbers(2020.01.01) Senturk, TD; Bilgici, G; Dasdemir, A; Unal, ZWeb of Science DIGITAL IMAGE FILTERING WITH NEW GENERALIZED ORDER-k JACOBSTHAL NUMBERS(2022.01.01) Ahmed, HMM; Dasdemir, APublication Dynamic response of a bi-axially pre-stressed bi-layered plate resting on a rigid foundation under a harmonic force(2020-02-01) Daşdemir A.; Dasdemir, AThis study aims to investigate the forced vibrations caused by a time-harmonic force from a pre-stressed bi-layered plate resting on a rigid foundation under the action of a time-harmonic pointwise loading. Our investigation was conducted according to a piecewise homogeneous body model utilizing the three-dimensional linearized theory of elastic waves in initially stressed bodies. Throughout this study, we assumed that there is complete contact between the plate and the rigid foundation. The purpose of this study is threefold: the development of a mathematical model to investigate the dynamic response of the pre-stressed bi-layered plate, the analysis of the frequency response of the plate under consideration, and finally, demonstrating the relationship between the initial stress and the dimensionless frequency of the plate. We solved the mathematical model by employing the finite element method. We present our numerical results on the dynamic behavior of the plate. In particular, we have shown that an increase in the values of the aspect ratio of a plate under fixed thickness leads to a decrease in the normal stress resonance values.Web of Science Publication Effect of imperfect bonding on the dynamic response of a pre-stressed sandwich plate-strip with elastic layers and a piezoelectric core(2017-12-01) Daşdemir A.; Dasdemir, AIn this paper, we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation. The investigation is carried out within the framework of the piecewise homogeneous body model by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity. It is assumed that there is a shear-spring-type imperfect contact between the layers, but a complete contact between the plate-strip and the rigid foundation. A mathematical model of the problem is constructed, and the governing equations of motion are solved by employing the finite element method (FEM). Numerical results illustrating the influence of a change in the value of the shear-spring parameter on the dynamic response of the plate-strip are then presented.Web of Science Web of Science Web of Science Publication Effects of poling direction and imperfection of interfaces on a pre-stressed system with a piezoelectric core bonded to elastic faces(2022-05-01) Daşdemir A.; Dasdemir, AThis paper models the resonance behavior of an initially stressed sandwich plate-strip consisting of a piezoelectric core and elastic faces, based on a rigid foundation, exposed to a time-harmonic force. Our research is conducted according to the linearized theory of electro-elasticity for solids under initial stress. This model assumes that there is a spring-type imperfectness at interfaces between the piezoelectric core and the face materials, both in the normal and tangential directions, and the core layer is poling in various directions. A mathematical model is created for the current problem, and then the finite element method (FEM) is used to solve it. Further, attention is focused on the influence of the mentioned imperfectness and the poling directions on the frequency response of plate-strip, in addition to the effects of the most important parameters on this response. The results show that as the imperfectness at the interface planes has the greatest effect on the horizontal polarization of the piezoelectric core, the mentioned polling direction inhibits the resonance mode of the system.Web of Science Web of Science Forced vibration of a bi-axially pre-stressed plate subjected to a harmonic point force and resting on a rigid foundation(2019.01.01) Dasdemir, A; Eroz, MWeb of Science FORCED VIBRATIONS OF PRE-STRESSED SANDWICH PLATE-STRIP WITH ELASTIC LAYERS AND PIEZOELECTRIC CORE(2018.01.01) Dasdemir, APublication Forced Vibrations of Pre-Stressed Sandwich Plate-Strip with Elastic Layers and Piezoelectric Core*(2018-07-01) Dașdemir A.; Dasdemir, AThe dynamical stress field in a sandwich plate-strip is mathematically modeled using the piecewise-homogeneous body model and the three-dimensional linearized theory of electro-elastic waves in initially stressed bodies. The plate consists of a piezoelectric core perfectly bonded to elastic layers with initial stress, rests on a rigid foundation, and is subject to harmonic force. It is assumed that the piezoelectric material is poled perpendicularly to the free surface of the body. The governing system of partial differential equations of motion is solved by the finite-element method. The numerical results are presented, illustrating the effect of certain relationships of the problem of the propagation of stresses and electric displacements at the interfaces between the elastic layers and the piezoelectric core and between the plate-strip and the rigid foundation. The effect of the initial stress parameter and a change in the thickness of the piezoelectric core on the frequency response of the plate-strip is studied.Web of Science Frequency Response of an Initially Stressed Slab Made from Three Compressible Materials(2021.01.01) Dasdemir, A