Makine Mühendisliği Bölümü Yayın Koleksiyonu

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  • Article
    Citation - Scopus: 5
    Fused Filament Fabrication in Cad Education: a Closed-Loop Approach
    (Sage Publications inc, 2025) Totuk, Onat Halis; Selvi, Ozguen; Akar, Samet
    Integrating low-cost fused filament fabrication 3D printing as a foundation for learning 3D modelling is explored. This method blends traditional computer aided design (CAD) instruction with additive manufacturing possibilities. Experimental results demonstrate increased comprehension speed and reduced learning time. This hands-on approach empowers students by enabling direct engagement with the modelling process. Analogous to reverse engineering, the strategy instructs engineering students from final product to model creation, closing the gap between theory and practice. Incorporating 3D printing bridges this divide, enhancing understanding, creativity and problem-solving. The study underscores technology's influence on learning strategies, aligning with the surge of 3D printing in education. Results link advanced design technology usage to improved student performance, with 3D-printed materials yielding 45% higher grades and 30% faster task completion. This study advocates curricular advancement for design-focused careers through enhanced technology integration and favourable 3D printing model reception.
  • Article
    Citation - Scopus: 3
    Numerical Simulation and Experimental Investigation: Metal Spinning Process of Stepped Thin-Walled Cylindrical Workpiece
    (Murat Yakar, 2022) Seyedzavvar, M.; Akar, S.; Abbasi, H.
    Many equipment and devices utilized in the aerospace industry are formed as symmetric parts through high plastic deformation of high strength sheet metal alloys with low thickness. Considering the inherent advantages of the spinning process of simple tooling and concentrated deformation loading, this process can be considered as one of the main options in producing these thin-sectioned lightweight parts. In this study, a Finite Element (FE) model has been developed to simulate the formation of a stepped thin-walled cylindrical workpiece of AISI 316 stainless steel alloy by spinning process. The FE simulation results were employed to investigate the effects of process parameters, including feed rate of the roller and rotational velocity of the mandrel on the distribution of stress and strain in the sheet metal, wrinkling failure, and thinning of the sheet metal during deformation. Experiments were carried out using selective input parameters based on the results of FE simulations. The comparison between FE simulations and experiments revealed that the developed model could predict the thinning of the sheet metals with over 93 % accuracy. Additionally, a good agreement between the experimentally deformed sheet configurations with those resulting from finite element simulations has been observed. © Author(s) 2022.
  • Article
    Strengthening Effect of Flooding in 3d Printed Porous Soft Robotics Scaffolds
    (2021) Arslan, Ozan; Selvi, Özgün; Mıstıkoglu, Selçuk; Totuk, Onat
    This study aims to design and 3D print porous elements for soft robotic applications and test the stiffness changes when the cavities are filled with liquids. When an elastic element has porous scaffolds, the stiffness can be controlled by filling the cavities with a liquid. A gyroid structure is selected for the design and evaluation of the characteristics of elements. The stiffness of the element in both non-filled and liquid-filled modes is analyzed using FEM simulation Software in two modes where simple support with central loading and compressive uniform loading. A porous test structure is created and tested in these modes for observation of the stiffness change. Employing an FDM printer in this project enabled us to make our thoughts to reality. The results show that liquid-filling can be used as a stiffening method for porous scaffolds in soft robotic applications.
  • Article
    Kesici Takım Geometrisinin Ti-6al-4v’nin İşlenmesi Sırasında Oluşan Tırtıklı Talaş Üzerindeki Etkisinin Sonlu Elemanlar Yöntemi ile Araştırılması
    (2020) Olıaei, Samad Nadimi Bavil; Yılmaz, Okan Deniz
    Ti-6Al-4V titanyum alaşımının işlenmesi sırasında tırtıklı talaş (serrated chip) oluşumunun modellenmesi oldukçazordur ve takım ömrünü, işlenmiş parçanın doğruluğunu ve yüzey kalitesini etkilediği için hayati öneme sahiptir.Kesici uç geometrisinin tırtıklı talaş oluşumu üzerindeki etkisi daha ileri araştırmalar gerektirirken, termalyumuşama, deformasyon yumuşaması ve hasara dayanan modeller olmak üzere bu sorunu çözmek için çeşitlimalzeme modelleri geliştirilmiştir. Bu çalışmada, teğet hiperbolik (TANH) fonksiyon kullanarak deformasyonyumuşama etkisini dikkate alan modifiye edilmiş bir Johnson-Cook temel malzeme modeli ele alınmıştır. Farklıgeometrilere (talaş açısı, boşluk açısı ve kenar yarıçapı) sahip olan kesici takımların tırtıklı talaş oluşumu üzerindeetkileri modellenmiş ve analiz edilmiştir. Kesme kuvveti, talaş morfolojisi ve tırtıklı talaşın derecesi talaşlı imalatverisi olarak kullanılmıştır
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Hybrid Force and Motion Control of a Three-Dimensional Flexible Robot Considering Measurement Noises
    (Mdpi, 2022) Kilicaslan, Sinan; Ozgoren, Mustafa Kemal; Ider, Sitki Kemal
    This work addresses the end-effector trajectory-tracking force and motion control of a three-dimensional three-link robot considering measurement noises. The last two links of the manipulator are considered as structurally flexible. An absolute coordinate approach is used while obtaining the dynamic equations to avoid complex dynamic equations. In this approach, each link is modeled as if there is no connection between the links. Then, joint connections are expressed as constraint equations. After that, these constraint equations are used in dynamic equations to decrease the number of equations. Then, the resulting dynamic equations are transformed into a form which is suitable for controller design. Furthermore, the dynamic equations are divided as pseudostatic equilibrium and deviation equations. The control torques resulting from the pseudostatic equilibrium and the elastic deflections are obtained easily as the solution of algebraic equations. On the other hand, the control torques corresponding to the deviations are obtained without any linearization. Encoders, strain gauges, position sensors and force and moment sensors are required for measurements. Low pass filters are considered for the sensors. For the crossover frequencies of the sensors, low and high values are chosen to observe the filtering effect on the robot output.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Analysis of Heat Transfer Enhancement in Tubes With Capsule Dimpled Surfaces and Al2o3-Water Nanofluid
    (Turkish Soc thermal Sciences Technology, 2022) Ibrahim, Mahmoud Awni A. Haj; Turkoglu, Hasmet; Yapici, Ekin Ozgirgin; Haj Ibrahim, Mahmoud Awni A.
    This study aims to numerically investigate and evaluate the enhancement of heat transfer by new capsule dimples on tube surfaces for flow of water and Al2O3-water nanofluid with different concentrations, under uniform surface heat flux. The originality of this work lies in combining two passive heat transfer enhancement methods such as geometrical improvements and nanofluids together. Capsule dimples with different depths were considered. Al2O3- water nanofluid was modeled as a single-phase flow based on the mixture properties. The effects of dimple depth and nanoparticle concentrations on Nusselt number, friction factor and performance evaluation criteria (PEC) were studied. Numerical computations were performed using ANSYS Fluent commercial software for 2000-14000 Reynolds number range. It was found that when laminar, transient and fully developed turbulent flow cases are considered, increase in the dimple depth increases the Nusselt number and friction factor for both pure water and Al2O3-water nanofluids cases. Also, the friction factor increases as dimple depth increases. Results show that increase in PEC is more pronounced in the laminar region than in the transition region, it starts to decrease for turbulent flows. For nanofluid, PEC values are considerably higher than pure water cases. The variation of PEC for capsule dimpled tubes are dependent on flow regimes and dimple depths. Increasing the nano particle volume concentration and dimple depth in laminar flows increase the PEC significantly.
  • Article
    Modeling and Optimization of a Peano-Hasel Actuator Peristaltic Pump
    (Natl inst Science Communication-niscair, 2023) Mistikoglu, Selcuk; Totuk, Onat Halis
    Peano-Hasel (hydraulically amplified self-healing electrostatic) pumps are crucial devices with unique mechanisms and versatile applications. They simulate muscle contractions to move fluids or materials through tubes. The Peano-Hasel method, a specific design, achieves flow by compressing a segmented tube externally. Exploring the design aspects of Peano-Hasel pumps can lead to advancements in optimizing their performance, efficiency, reliability, and control systems. This paper presents a novel method of peristaltic pumping on soft pipes using Peano-HASEL actuators. In the study, a design evaluation of an external ring-type pump over a PDMS (Polydimethylsiloxane -commonly referred to as silicone) tube containing Newtonian fluids is made, and a novel multi-pouch ring shape design is proposed. Our method utilizes a peripheral and compact design that allows for more efficient sinusoidal pumping action. The close proximity of the rings in the longitudinal direction enhances the effectiveness of the pumping process. The actuator is analytically modeled and optimized for maximum areal contraction and flow rate using a differential evolution algorithm. A MATLAB Simulink Simscape model is generated, and the system is simulated. As a result, an optimal solution for the number of pouches was found to be eight, considering ring geometry and applicability. It was also seen from the simulation that a sinusoidal squeezing scheme of a ring-type pump creates the desired action. Based on the analytical model presented, it has been demonstrated that the optimal flow rate is achieved when there are eight pouches, and they are fully circular after being energized.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 11
    Modeling of Computer Virus Propagation With Fuzzy Parameters
    (Tech Science Press, 2023) Ahmed, Nauman; Baleanu, Dumitru; Fatima, Umbreen; Dayan, Fazal; Rafiq, Muhammad; Mahmoud, Emad E.; Alhebshi, Reemah M.
    Typically, a computer has infectivity as soon as it is infected. It is a reality that no antivirus programming can identify and eliminate all kinds of viruses, suggesting that infections would persevere on the Internet. To understand the dynamics of the virus propagation in a better way, a computer virus spread model with fuzzy parameters is presented in this work. It is assumed that all infected computers do not have the same contribution to the virus transmission process and each computer has a different degree of infectivity, which depends on the quantity of virus. Considering this, the parameters beta and gamma being functions of the computer virus load, are considered fuzzy numbers. Using fuzzy theory helps us understand the spread of computer viruses more realistically as these parameters have fixed values in classical models. The essential features of the model, like reproduction number and equilibrium analysis, are discussed in fuzzy senses. Moreover, with fuzziness, two numerical methods, the forward Euler technique, and a nonstandard finite difference (NSFD) scheme, respectively, are developed and analyzed. In the evidence of the numerical simulations, the proposed NSFD method preserves the main features of the dynamic system. It can be considered a reliable tool to predict such types of solutions.
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Experimental Investigation Into the Effect of Magnetorheological Fluid Damper on Vibration and Chatter in Straight Turning Process
    (Elsevier Sci Ltd, 2023) Nasab, Vahid Hasan; Akar, Samet; Batako, Andre; Emami, Mohsen
    Magneto-Rheological (MR) dampers have received a great deal of attention in recent years due to the potential of offering semi-active control. MR dampers have been successfully applied in the vibration control of several machining processes. However, the effect of the material of the damper's fluid chamber on its magnetic prop-erties has not been studied much. In this study, an MR damper has been designed to control the chatter vibration of the straight turning operation. The magnetic properties of the MR damper are simulated in the FEM software COMSOL Multiphysics with two types of steel AISI 410 and AISI 1018, and the material with the best perfor-mance for constructing the fluid chamber is determined. Then, the MR damper with an assembly to hold the cutting tool was fabricated and experimentally tested during straight turning operation and its effect on the tool vibration, and work surface roughness was analyzed. From the result, it was observed that the MR damper reduced tool vibration and chatter effectively. The results obtained in this research confirm that the application of the MR damper in the straight-turning process can either suppress the chatter or greatly reduce the frequency amplitude of the chatter. The reduction of the tool's acceleration amplitude with the MR damper was more intense in the condition of chatter suppression and reached up to 89.42 %. Moreover, the MR damper reduced the roughness of the machining surface. This reduction was higher in cases where the chatter was suppressed and it was observed up to 29 %.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Comprehensive Elastic Analysis of Functionally Graded Variable Thickness Pressurized Disk
    (Wiley-v C H verlag Gmbh, 2023) Farukoglu, oemer Can; Korkut, Ihsan; Motameni, Ali
    This study analytically examines internally pressurized power-law functionally graded variable thickness disk. The power-law consideration is applied to the Young's modulus and the Poisson's ratio of the graded material as well as the radial thickness profile variation of the disk. Under this scheme, the solution yields to different Bessel functions including the first, second, and modified types. Stress and displacement fields are investigated at the elastic limits by operating with these functions. The limits are calculated with the well-known von Mises criteria. Following the analytical modeling, numerical examples are built. Therein the examples, some noteworthy nuances have been achieved. It has been observed that unlike the usual prediction in the literature, constant Poisson's ratio, the effect of variable Poisson's ratio on stresses and displacements is still evident, although not as much as variable Young's modulus and disk geometry. We suggest assigning it as a variable in similar applications to be more precise. Additionally, according to the von Mises criterion, yielding may begin at the inner radius, the outer radius, or both at the same time. Parameters in the simultaneous flow initiation state are critical. These parameters allow the disk to reach the highest elastic limit pressure.