Browsing by Author "Baranoglu, Besim"

Now showing 1 - 11 of 11

An Adaptive Element Division Algorithm for Accurate Evaluation of Singular and Near Singular Integrals in 3d
(Tubitak Scientific & Technological Research Council Turkey, 2021) Bayindir, Hakan; Baranoglu, Besim; Yazici, Ali; Software Engineering; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
An adaptive algorithm for evaluation of singular and near singular integrals in 3D is presented. The algorithm is based on successive adaptive/selective subdivisions of the element until a prescribed error criteria is met. For evaluating the integrals in each subdivision, Gauss quadrature is applied. The method is computationally simple, memory efficient and can be applied for both triangular and quadrilateral elements, including the elements with nonplanar and/or curved surfaces. To assess the method, several examples are discussed. It has shown that the algorithm performs well for singular and near-singular integral examples presented in the paper and evaluates the integrals with very high accuracy.
Citation - WoS: 3
An Application of High-Power Electromagnetic Pulse: Forming of Sheet Metal Using Electromagnetic Waves
(Ieee, 2015) Inanan, Gokhan; Baranoglu, Besim; Aydin, Elif; Department of Electrical & Electronics Engineering; Manufacturing Engineering; 15. Graduate School of Natural and Applied Sciences; 06. School Of Engineering; 01. Atılım University
In this study, the application of high velocity metal forming process by means of electromagnetic field is proposed. Electromagnetic Sheet Metal Forming (ESMF) is a process of forming sheet metal with very high speed (in milliseconds) without mechanical contact using the energy density of a pulsed magnetic field. In this process, deformation of the workpiece is driven by a transient electric current that is induced in a coil using a capacitor bank and discharge switch. This study presents some experiments and their results by examining the effects of different parameters in the proposed ESMF setup. The analysis and modelling of Electromagnetic sheet metal forming (ESMF) process is presented, as well. It has been seen that, it is possible to design a new system using the outcomes of this study.
Citation - WoS: 1
Citation - Scopus: 3
Boundary Element Method for Optical Force Calibration in Microfluidic Dual-Beam Optical Trap
(Spie-int Soc Optical Engineering, 2015) Solmaz, Mehmet E.; Cetin, Barbaros; Baranoglu, Besim; Serhathoglu, Murat; Biyikh, Neemi; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
The potential use of optical forces in microfluidic environment enables highly selective bio-particle manipulation. Manipulation could be accomplished via trapping or pushing a particle due to optical field. Empirical determination of optical force is often needed to ensure efficient operation of manipulation. The external force applied to a trapped particle in a microfluidic channel is a combination of optical and drag forces. The optical force can be found by measuring the particle velocity for a certain laser power level and a multiplicative correction factor is applied for the proximity of the particle to the channel surface. This method is not accurate especially for small microfluidic geometries where the particle size is in Mie regime and is comparable to channel cross section. In this work, we propose to use Boundary Element Method (BEM) to simulate fluid flow within the micro-channel with the presence of the particle to predict drag force. Pushing experiments were performed in a dual-beam optical trap and particle's position information was extracted. The drag force acting on the particle was then obtained using BEM and other analytical expressions, and was compared to the calculated optical force. BEM was able to predict the behavior of the optical force due to the inclusion of all the channel walls.
A Coupled Modelling and Simulation Approach to Electromagnetic Sheet Metal Forming
(Taylor & Francis Ltd, 2025) Aslan, Ozgur; Kabakci, Gamze Cakir; Sait, Ferit; Camalan, Caner; Baranoglu, Besim; Bayraktar, Emin; Aerospace Engineering; Mechanical Engineering; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
This study presents a coupled numerical and experimental investigation of electromagnetic forming (EMF) for aluminium sheets. A custom simulation framework is developed in ABAQUS/Standard using user-defined material (UMAT) and load (DLOAD) subroutines. The magnetic pressure exerted on the workpiece is computed through a finite difference-based solution of Maxwell's equations and applied to the mechanical solver. The mechanical response of the material is modelled using a strain-rate-sensitive plasticity law calibrated for aluminium 7075-O. Experimental forming trials are performed using a custom-built EMF setup, and the results are compared with numerical predictions to validate the model. The comparison shows strong agreement in deformation profiles, confirming the predictive capability of the proposed simulation strategy. This work offers a reliable computational tool for optimising EMF processes and provides insights into material behaviour under high strain rate electromagnetic loading.
Citation - WoS: 4
Citation - Scopus: 5
Isogeometric Boundary Element Formulation for Cathodic Protection of Amphibious Vehicles
(Elsevier Sci Ltd, 2024) Gumus, Ozgur Can; Atak, Kaan; Cetin, Baris; Baranoglu, Besim; Cetin, Barbaros; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
In this study, we propose an isogeometric boundary element formulation for the cathodic protection (CP) modeling for amphibious vehicles which includes the treatment of non-linear boundary conditions. Half-space Green's functions are utilized which leads to the discretization of the hull surface only. Non-Uniform Rational B splines (NURBS) are employed to represent both geometry and field variables to obtain higher accuracy where discontinuous collocation points are utilized to make multi-patch implementation easier. Variable condensation technique is applied to manipulate system matrices in a such way that the solution is iterated only on the surfaces where non-linear boundary conditions are assigned which results in reduced computational cost. The computational performance of the formulation is assessed with different solvers for a representative hull geometry.
Citation - WoS: 21
Citation - Scopus: 27
Modeling of Dielectrophoretic Particle Motion: Point Particle Versus Finite-Sized Particle
(Wiley, 2017) Cetin, Barbaros; Oner, S. Dogan; Baranoglu, Besim; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
Dielectrophoresis (DEP) is a very popular technique for microfluidic bio-particle manipulation. For the design of a DEP-based microfluidic device, simulation of the particle trajectory within the microchannel network is crucial. There are basically two approaches: (i) point-particle approach and (ii) finite-sized particle approach. In this study, many aspects of both approaches are discussed for the simulation of direct current DEP, alternating current DEP, and traveling-wave DEP applications. Point-particle approach is implemented using Lagrangian tracking method, and finite-sized particle is implemented using boundary element method. The comparison of the point-particle approach and finite-sized particle approach is presented for different DEP applications. Moreover, the effect of particle-particle interaction is explored by simulating the motion of closely packed multiple particles for the same applications, and anomalous-DEP, which is a result of particle-wall interaction at the close vicinity of electrode surface, is illustrated.
Citation - WoS: 8
Citation - Scopus: 9
A Multi-Domain Direct Boundary Element Formulation for Particulate Flow in Microchannels
(Elsevier Sci Ltd, 2021) Topuz, Alper; Baranoglu, Besim; Cetin, Barbaros; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
In the present study, a multi-domain boundary element formulation is developed for high surface-area-to-volume ratio problems (i.e. particulate flow in high aspect ratio microfluidic channels, in a porous medium or in microfluidic devices with repetitive structures). The solution domain is decomposed into subdomains and the variable condensation technique is implemented. The solution matrices are built for each subdomain, and the matrices are updated at each time step only for the subdomains in which the particles move at each time step. Ghost domains, which are fictitious domains encapsulating the interfaces between the subdomains, are also introduced in the formulation to treat the particles crossing the interfaces between the subdomains. The formulation reveals that the computation of the subdomain matrices is further simplified for solution domains composed of periodic structures. The results of our study revealed that speed-up values as high as 50 is achievable with the current formulation.
Citation - WoS: 1
A NEW FORMULATION FOR THE BOUNDARY ELEMENT ANALYSIS OF HEAT CONDUCTION PROBLEMS WITH NONLINEAR BOUNDARY CONDITIONS
(Turkish Soc thermal Sciences Technology, 2019) Baranoglu, Besim; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
An effective numerical method based on the boundary element formulation is presented to solve heat conduction equations which are governed by the Fourier equation, with nonlinear boundary conditions on one or more sections of the prescribed boundary. The solution involves the manipulation of the system matrices of the boundary element method and obtaining a smaller ranked matrix equation in which the unknown is only the temperature difference over the nonlinear boundary condition region. This way, the iterations to deal with the nonlinear conditions are performed faster. After finding the solution over the nonlinear boundary condition region, the solution over the entire boundary is obtained as a post-process through a prescribed relation. An example with a proven exact solution is employed to assess the results.
Citation - WoS: 7
Citation - Scopus: 7
Nodular Cast Iron Ggg40, 60, 70 Mechanical Characterization From Bars and Blocks Obtained From Brazilian Foundry
(Mdpi, 2022) Fernandes, Daniel de Oliveira; Mota Anflor, Carla Tatiana; Vaz Goulart, Jhon Nero; Baranoglu, Besim; Manufacturing Engineering; 06. School Of Engineering; 01. Atılım University
Nodular cast iron has been commonly applied in industry and many engineering applications due to its low production cost and the similarity of its mechanical properties to carbon steel. The mechanical properties of nodular cast iron are very dependent on its microstructure and also on the characteristics of the graphite nodules. In this sense, the main objective of this paper was to evaluate and characterize the nodular cast iron grades GGG40, GGG60 and GGG70 in the absence of heat treatment. In addition, specimens were obtained from casted bars and blocks without the Y-block casting process. The microstructure was analyzed by optical microscopy with the support of computational image analysis for determination of the attributes of the graphite nodules and the quantification of each phase present in the microstructure of the nodular cast iron. The results showed that the microstructure has a strong effect on the material's strength, especially the density of graphite nodules in the material. This difference reinforces the idea that cast iron can undergo mechanical changes due to changes in the casting process, confirming the importance of checking the characteristics of the cast batch before engineering applications of the material.
Predicting the Topology of the Bending Corner in Bending of Ultra High Strength Steels Through Finite Element Analysis
(Tanger Ltd, 2019) Cetin, Baris; Billur, Eren; Baranoglu, Besim; Toptas, Ugur; Alic, Ozgur; Manufacturing Engineering; Automotive Engineering; Manufacturing Engineering; Automotive Engineering; 06. School Of Engineering; 01. Atılım University
In bending of plates, unlike the case of sheet metal forming, a 3-D stress state is valid. Moreover, apart from the some very specific cases, the plane strain assumption is not appropriate either. Therefore; bending of thick ultra-high strength steel (UHSS) plates is a deformation process where 3-D stress and strain states exist in general. This study basically focuses on the prediction of the bending corner topology with non-linear finite element analysis method, since the laser-cut edges of the UHSS are particularly prone to edge cracking during bending operation. Within the scope of this study, an experimental set-up is designed which consists of bending tools and a servo mechanical press. The samples were bent by means of this set-up in an air-bending operation up to 90 degrees. This experimental work was followed by optical scanning measurements. And finally, the FEA results and the scanning data were compared in 3-D space. The results showed good correlation. As a future study, the 3-D strain field of the bending corner will be tried to be measured by a professional digital image correlation (DIC) system which could probably give more precise data when combined with the data from FEA.
Citation - WoS: 7
Citation - Scopus: 8
Robust and Adaptive Control Design of a Drilling Rig During the Operating Modes
(Sage Publications Ltd, 2019) Sadeghi, Amir Nobahar; Arikan, Kutluk Bilge; Ozbek, Mehmet Efe; Baranoglu, Besim; Mechatronics Engineering; Department of Mechatronics Engineering; Department of Electrical & Electronics Engineering; Manufacturing Engineering; 15. Graduate School of Natural and Applied Sciences; 06. School Of Engineering; 01. Atılım University
Oil well drilling towers have different operating modes during a real operation, like drilling, tripping, and reaming. Each mode involves certain external disturbances and uncertainties. In this study, using the nonlinear model for the modes of the operation, robust and/or adaptive control systems are designed based on the models. These control strategies include five types of controllers: cascaded proportional-integral-derivative, active disturbance rejection controller, loop shaping, feedback error learning, and sliding mode controller. The study presents the design process of these controllers and evaluates the performances of the proposed control systems to track the reference signal and reject the uncertain forces including the parametric uncertainties and the external disturbances. This comparison is based on the mathematical performance measures and energy consumption. In addition, three architectures are presented to control the weight on bit during drilling process, and also to maintain a preset constant weight on bit, two control approaches are designed and presented.