Yazar "Evran, Savas" seçeneğine göre listele

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    Cutting Rate and Surface Characteristic Analysis in CNC Wire Electrical Discharge Machining of Aluminium Bronze
    (Univ Osijek, Tech Fac, 2019) Evran, Savas; Mutlu, Bilcen; Kurt, Mustafa
    In this study, cutting rate and surface characteristic analysis in wire electrical discharge machining of aluminium bronze were investigated. Cutting rate analyses were performed according to Taguchi L18 (2(1)x3(2)) orthogonal array. Machining parameters such as wire type, duration between two pulses (Br) and pulse time (AT) were used as control factors. Raw data obtained for cutting rate were converted to S/N ratio values. Optimum levels of the machining parameters for cutting rate were determined using analysis of signal-to-noise (S/N) ratio. Significant machining parameters and their percentage contributions on results were obtained using Analysis of Variance (ANOVA). Regression analysis was performed to model the relationship between cutting rate and machining parameters. Analyses of surfaces machined of workpiece using both two wires for minimum and maximum cutting rate were observed using scanning electron microscope (SEM) and surface roughness device.
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    Evaluation of Cross-Section and Wing Length in Free Vibration Analysis ofAircraft Wings
    (2020) Evran, Savas; Kurt, Mustafa; Kurt, Arzu
    This study presents the numerical free vibration analysis of aircraft wings created using different airfoil cross sections such as NACA 0009, NACA 2424, and NACA 4415. Aircraft wings were made of different lengths. Numerical frequency analyses were conducted Taguchi L9 orthogonal array with two control factors including three levels and so nine numerical modal analyses were performed. Airfoil cross sections and lengths of aircraft wings were used as the first and the second control factors. To detect the control factors with optimal levels, analysis of signal-to-noise (S/N) ratio was employed. In addition, analysis of variance (ANOVA) at the 95 % confidence level was implemented to carry out percent contributions of airfoil cross sections and lengths of aircraft wings on free vibration. As can be summarized from this study, the maximum free vibration behavior was obtained by using NACA 2424 wing profiles with a length of 5 meters. Also, the most dominant control factors were found to be airfoil type with 85.21 % effect and wing length with 12.87 % effect, according to ANOVA.
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    Experimental and statistical free vibration analyses of laminated composite beams with functionally graded fiber orientation angles
    (Sage Publications Ltd, 2020) Evran, Savas
    In this experimental and statistical study, free vibration behavior of laminated composite beams with functionally graded fiber orientation angles was investigated under clamped-free boundary conditions. The beams were manufactured using E-glass/epoxy. Fiber orientation angles of the beams were analyzed based on Taguchi's L9 (3(3)) orthogonal array. The effect of fiber orientation angles and beams with optimum levels were assessed using analysis of signal-to-noise ratio. Significant laminates of the beams and their percent contributions on the free vibration responses were obtained using analysis of variance. According to this study, the increase of fiber orientation angle from 0 degrees to 80 degrees causes a decrease in the fundamental frequency behavior of laminated composite beams. The most effective control factors were found to be the first and the second laminates symbolized as L1 with 85.86% contribution, the third and the fourth laminates symbolized as L2 with 12.29% contribution, the fifth and the sixth laminates symbolized as L3 with 1.84% contribution, respectively. This study can be used as a reference for free vibration analysis of cantilever laminated composite beams made of functionally graded fiber orientation angles as experimentally and statistically.
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    Free vibration analysis of axially layered functionally graded short beams using experimental and finite element methods
    (Walter De Gruyter Gmbh, 2016) Yilmaz, Yasin; Evran, Savas
    Free vibration behavior of short beams made of axially layered functionally graded material (FGM) was investigated experimentally and numerically. Beams, which have gradation of the material properties in the axial direction, are fabricated by powder metallurgy technique using different weight fractions of aluminum and silicon carbide powders. In order to determine elasticity modulus of axially layered functionally graded (FG) beams, homogeneous beams containing different weight fractions of Al (aluminum) and SiC (silicon carbide) are produced, and these homogeneous beams are subjected to tensile tests. Density of each homogeneous layer is also calculated experimentally. After determination of the mechanical properties of each layer of the FG beams, they are modeled in a finite element program (ANSYS) according to Timoshenko beam theory, and free vibration analyses are performed. Fundamental frequencies of the axially layered FG beams produced are also calculated experimentally. FG beams with clamped-free boundary conditions are considered. Layers of the axially FG beams are considered to have symmetric configurations. Effect of the change in weight fractions of SiC particles and sorting order of layers to fundamental frequency of the beam is investigated. Experimental results obtained are compared with numerical results.
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    Investigation of Effects of Fiber Orientation Angles on Deflection Behavior of Cantilever Laminated Composite Square Plates
    (Gazi Univ, 2020) Evran, Savas
    In this study, the deflection response of cantilever laminated composite square plates subjected to the weight of itself was analyzed using finite element and Taguchi methods. The plates with 12 plies were made of glass fiber reinforced polymer composites (GFRP). The arrangements and fiber orientation angles of the plies were conducted using Taguchi's L9 (33) orthogonal array. Each four plies was assumed to be control factor. Fiber orientation angles were varied from 10 to 90 in degree. Plates were modelled using finite element software ANSYS Parametric Design Language. Analysis of signal-to-noise (S/N) ratio was used in order to evaluate the control factors with the optimum levels for minimum deflection response. Analysis of variance was carried out in order to analyze the powerful influential control factors and their percent contributions on responses.
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    Investigation of effects of layer positions on mechanical buckling behavior of axially layered functionally graded beams
    (Pamukkale Univ, 2019) Evran, Savas
    The aim of this research is to examine the mechanical buckling behavior of multi-layered functionally graded beams in the axial direction. Numerical buckling analyses were performed using finite element software called ANSYS. Each beam configuration is suggested to be three layers prepared using various percent volume fractions of Zirconia (ZrO2) and Aluminum (Al) materials. The levels of layers and layer positions of the beams were evaluated according to Taguchi's L-9 (33) orthogonal array technique. Layers were determined as control factor and so nine numerical analyses were performed under clamped-clamped boundary conditions. The first mode shapes of the axially layered functionally graded beams were demonstrated in order to detect the most affected layers as visually. Analysis of signal-to-noise ratio was applied to obtain the optimum levels of layers. Analysis of Variance (ANOVA) was employed to solve the layers with significant impacts and their percent contributions on numerical results. The maximum buckling load was determined using various positions of layers with the optimum levels obtained based on Taguchi methodology.
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    Numerical and Statistical Aerodynamic Performance Analysis of NACA0009 and NACA4415 Airfoils
    (Gazi Univ, 2024) Evran, Savas; Yildir, Salih Zeki
    In this numerical and statistical study, lift and drag coefficient performances of NACA-0009 and NACA-4415 airfoils were evaluated in accordance with various attack angle at constant velocity of wind. Lift and drag coefficients of airfoils was numerically determined by computational fluid dynamics code ANSYS FLUENT. Analysis design of numerical calculations was implemented using L16 orthogonal array based on Taguchi method. Angles of attack and airfoil types were considered as control factors. The optimum level and effect of each control factor on responses was statistically implemented using analyses of Signal-to-Noise ratio and variance. As a result of this study, maximum lift and minimum drag coefficient were achieved by using NACA4415 airfoil compared to NACA0009 airfoil. The increase of the angle of attack leads to the increase on the lift and drag coefficients for both airfoils.
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    Numerical and statistical buckling analysis of laminated composite plates with functionally graded fiber orientation angles
    (Sage Publications Ltd, 2020) Evran, Savas
    The aim of this numerical and statistical study was to investigate the buckling analysis of laminated composite plates containing functionally graded fiber orientation angles. The laminated composite plates had functionally graded fiber orientation angles based on Taguchi's L18 (2(1)x 3(2)) orthogonal array. The fiber orientation angles were considered to be control factors. Numerical analyses were performed using finite element software ANSYS. The optimum critical buckling load and the effects of fiber orientation angles for maximum data were determined using the analysis of the signal-to-noise ratio. The importance levels of laminates and their percent contribution on the buckling characteristics were calculated using analysis of variance. Regression analysis was employed to investigate the effects of control factors on buckling responses mathematically. The effects of laminate stacking sequence, mesh size, element type, mode number, and boundary condition were carried out using laminates with the optimum levels.
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    Surface roughness and material removal rate analyses of hard copper alloy in wire electrical discharge machining
    (Ice Publishing, 2020) Evran, Savas
    This experimental and statistical study focuses on investigation of the effects of machining parameters on surface roughness (SR) and material removal rate (MRR) in wire electrical discharge machining (WEDM) of hard copper (Cu) alloy. Experimental design was carried out using the L18 (2(1) x 3(2)) orthogonal array according to the Taguchi method. The process parameters considered were wire type, pulse time and duration between two pulses. Copper-coated wire and zinc (Zn)-coated wires were used as cutting tools. Analysis of the signal-to-noise (S/N) ratio was utilized to investigate the effects of process parameters on the responses. Analysis of variance was employed to determine the percent contributions and significance levels of process parameters on responses. Analysis of the surface integrity and characteristics of the machined specimens was observed using scanning electron microscopy, and energydispersive X-ray spectroscopy analysis was employed. This study may be used as a reference to investigate SR and MRR in WEDM of hard copper alloy.
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    Thermal Buckling Analysis of Axially Layered Functionally Graded Thin Beams under Clamped-Clamped Boundary Conditions
    (Gazi Univ, 2019) Evran, Savas
    In the present article, the critical buckling temperature of axially layered functionally graded thin beams for the first mode was studied under clamped-clamped boundary conditions. The beams were made to be three layers using functionally graded materials with ceramic and metal systems in the axial direction. Analyses were performed using fmite element and Taguchi methods. The beam configurations were designed based on Taguchi L-9 orthogonal array in order to detect the maximum critical buckling temperature and were analyzed using finite element software ANSYS. Analysis of signal-to-noise ratio was utilized to determine the layers with optimum levels and the influence of ceramic and metal materials in each layer. Analysis of Variance at the 95 % confidence level was employed in order to select the most significant layers and their percent contribution on response characteristic. The optimum result of the critical buckling temperature was predicted based on the 95 % confidence intervals of confirmation analysis and population.
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    Twisting Angle Analysis of Laminated Composite Plates Using Numerical and Statistical Methods
    (2019) Evran, Savas
    This study deals with the investigation of the effects of fiber orientationangles on the analysis of angle of twist of laminated composite plates under cantileverboundary conditions with left edge clamped and remaining edges free (C-F-F-F).Numerical twisting angle analyses were conducted based on Taguchi’s L8 ortogonalarray. The plates were designed using 8 plies and each two plies was determined to be acontrol factor. The fiber orientation angles in each control factor were assumed to varyfrom 100 to 800 through the axial direction. Analysis of signal-to-noise (S/N) ratio wasperformed to see the effects of fiber angles and to determine the optimum levels forminimum twisting angle. Analysis of Variance (ANOVA) was applied to analyze thesignificant control factors and percent contributions on the twisting angle results.Regression analysis was employed mathematically in order to see the effects of the fiberangles on the response. According to ANOVA result, the most effective control factorswere found to be D with 87.51 %, C with 10.26 %, A with 1.22 %, and B with 0.04 %respectively.