Research of the impact of material and flow properties on fluid-structure interaction in cage systems

Mehmet Emin Özdemir,Murat Yaylacı 한국풍공학회 2023 Wind and Structures, An International Journal (WAS Vol.36 No.1

This paper investigates the mechanical behavior of full-scale offshore fish cages under hydrodynamic loads. To simulate different cases, different materials were used in the fish cage and analyzed under different flow velocities. The cage system is studied in two parts: net cage and floating collar. Analyses were performed with the ANSYS Workbench program, which allows the Finite Element Method (FEM) and Computational Fluid Dynamics (CFD) method to be used together. Firstly, the fish cage was designed, and adjusted for FSI: Fluid (Fluent) analysis. Secondly, mesh structures were created, and hydrodynamic loads acting on the cage elements were calculated. Finally, the hydrodynamic loads were transferred to the mechanical model and applied as a pressure on the geometry. In this study, the equivalent (von Mises) stress, equivalent strain, and total deformation values of cage elements under hydrodynamic loads were investigated. The data obtained from the analyses were presented as figures and tables. As a result, it has been shown that it is appropriate to use all the materials examined for the net cage and the floating collar.

Solving the contact problem of functionally graded layers resting on a HP and pressed with a uniformly distributed load by analytical and numerical methods

Murat Yaylacı,Bahar Şengül Şabano,Mehmet Emin Özdemir,Ahmet Birinci 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.3

The aim of this study is to examine the frictionless double receding contact problem for two functionally graded (FG) layers pressed with a uniformly distributed load and resting on a homogeneous half plane (HP) using analytical and numerical methods. The FG layers are made of a non-homogeneous material with an isotropic stress-strain law with exponentially varying properties. It is assumed that the contact at the FG layers and FG layer-HP interface is frictionless. The body force of the FG layers and homogeneous HP are ignored in the study. Firstly, an analytical solution for the contact problem has been realized using the theory of elasticity and the Fourier integral transform techniques. Then, the problem modeled and two-dimensional analysis was carried out by using the ANSYS package program based on FEM. Numerical results for contact lengths and contact pressures between FG layers and FG layer-HP were provided for various dimensionless quantities including material inhomogeneity, distributed load width, the shear module ratio, and the heights of the FG layers for both methods. The results obtained using FEM were compared with the results found using the analytical formulation. It was found that the results obtained from analytical formulation were in perfect agreement with the FEM study.

Application of artificial neural networks in the analysis of the continuous contact problem

Ecren Uzun Yaylacı,Erdal Öner,Murat Yaylacı,Mehmet Emin Özdemir,Ahmad Abushattal,Ahmet Birinci 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.1

This paper investigates the artificial neural network (ANN) to predict the dimensionless parameters for contact pressures and contact lengths under the rigid punch, the initial separation loads, and the initial separation distances of a contact problem. The problem consisted of two elastic infinitely layers (EL) loaded by means of a rigid cylindrical punch and resting on a half-infinite plane (HP). Firstly, the problem was formulated and solved theoretically using the Theory of Elasticity (ET). Secondly, the contact problem was extended based on the ANN. External load, the radius of punch, layer heights, and material properties were created by giving examples of different values used at the training and test stages of ANN. Finally, the accuracy of the trained neural networks for the case was tested using 134 new data, generated via ET solutions to determine the best network model. ANN results were compared with ET results, and well agreements were achieved.

Vibration and buckling analyses of FGM beam with edge crack: Finite element and multilayer perceptron methods

Murat Yaylacı,Ecren Uzun Yaylacı,Mehmet Emin Özdemir,Şevval Öztürk,Hasan Sesli 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.4

This study represents a numerical research in vibration and buckling of functionally graded material (FGM) beam comprising edge crack by using finite element method (FEM) and multilayer perceptron (MLP). It is assumed that the material properties change only according to the exponential distributions along the beam thickness. FEM and MLP solutions of the natural frequencies and critical buckling load are obtained of the cracked FGM beam for clamped–free (C-F), hinged–hinged (H-H), and clamped–clamped (C-C) boundary conditions. Numerical results are obtained to show the effects of crack location (c/L), material properties (E2/E1), slenderness ratio (L/h) and end supports on the bending vibration and buckling properties of cracked FGM beam. The FEM analysis used in this paper was verified with the literature, and the fundamental frequency ratio ( ̅) and critical buckling load ratio ( ̅̅̅̅) results obtained were compared with FEM and MLP. The results obtained are quite compatible with each other

Implementation of finite element and artificial neural network methods to analyze the contact problem of a functionally graded layer containing crack

Murat Yaylacı,Ecren Uzun Yaylacı,Mehmet Emin Özdemir,Sevil Ay,Şevval Öztürk 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.4

In this study, a two-dimensional model of the contact problem has been examined using the finite element method (FEM) based software ANSYS and based on the multilayer perceptron (MLP), an artificial neural network (ANN). For this purpose, a functionally graded (FG) half-infinite layer (HIL) with a crack pressed by means of two rigid blocks has been solved using FEM. Mass forces and friction are neglected in the solution. Since the problem is analyzed for the plane state, the thickness along the z-axis direction is taken as a unit. To check the accuracy of the contact problem model the results are compared with a study in the literature. In addition, ANSYS and MLP results are compared using Root Mean Square Error (RMSE) and coefficient of determination (R2), and good agreement is found. Numerical solutions are made by considering different values of external load, the width of blocks, crack depth, and material properties. The stresses on the contact surfaces between the blocks and the FG HIL are examined for these values, and the results are presented. Consequently, it is concluded that the considered non-dimensional quantities have a noteworthy influence on the contact stress distributions, and also, FEM and ANN can be efficient alternative methods to time-consuming analytical solutions if used correctly.

Finite element analysis of the behavior of elliptical cracks emanating from the orthopedic cement interface in total hip prostheses

Ali Benouis,Mohammed El Sallah Zagane,Abdelmadjid Moulgada,Murat Yaylacı,Djafar Ait Kaci,Merve Terzi,Mehmet Emin Özdemir,Ecren Uzun Yaylacı 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.5

This study examines crack behavior within orthopedic cement utilized in total hip replacements through the finite element method. Its main goal is to compute stress intensity factors (SIF) near the crack tip. The analysis encompasses two load types, static and dynamic, applied to a crack starting from the interface between the cement and bone. Specifically, it investigates SIFs under mixed mode conditions during three activities: normal walking, climbing upstairs, and downstairs. The results highlight that a crack originating from a micro-interface under substantial loading can cause cement damage, leading to prosthetic loosening. Stress intensity factors in modes I, II, and III are influenced by the crack tip’s orientation and location in the bone cement, with a 90° orientation yielding notably higher values across all three modes.

Finite element analysis of ratcheting on beam under bending-bending loading conditions

Sk. Tahmid Muhatashin Fuyad,Md Abdullah Al Bari,Md. Makfidunnabi,H.M. Zulqar Nain,Mehmet Emin Özdemir,Murat Yaylacı 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.89 No.1

Ratcheting is the cyclic buildup of inelastic strain on a structure resulting from a combination of primary and secondary cyclic stress. It can lead to excessive plastic deformation, incremental collapse, or fatigue. Ratcheting has been numerically investigated on a cantilever beam, considering the current study’s primary and secondary bending loads. In addition, the effect of input frequency on the onset of ratcheting has been investigated. The non-linear dynamic elastic-plastic approach has been utilized. Analogous to Yamashita’s bending-bending ratchet diagram, a non-dimensional ratchet diagram with a frequency effect is proposed. The result presents that the secondary stress values fall sequentially with the increase of primary stress values. Moreover, a displacement amplification factor graph is also established to explain the effect of frequency on ratchet occurrence conditions. In terms of frequency effect, it has been observed that the lower frequency (0.25 times the natural frequency) was more detrimental for ratchet occurrence conditions than the higher frequency (2 times the natural frequency) due to the effect of dynamic displacement. Finally, the effect of material modeling of ratcheting behavior on a beam is shown using different hardening coefficients of kinematic hardening material modeling.