... Bu amaçla, KÜ teknolojisindeki bilgi gereksinmeleri ve hali haz rda kullan lan ve ara tr lan ... more ... Bu amaçla, KÜ teknolojisindeki bilgi gereksinmeleri ve hali haz rda kullan lan ve ara tr lan bilgi transfer protokolleri incelenmi ve yeni bir bilgi transfer format ihtiyac belirlenmi tir. Anahtar Kelimeler : Katmanl Üretim, H zl Prototipleme, KÜ, bilgi transferi, stl. ...
Bilgisayar destekli tasarım verilerinin kullanımı, CAD içerisindeki tasarım modelinin islem planl... more Bilgisayar destekli tasarım verilerinin kullanımı, CAD içerisindeki tasarım modelinin islem planlaması için unsur modeline dönüstürülmesi asamasında önemli ölçüde is ve zaman tasarrufu sağlamaktadır. Bu çalısmada amaçlanan, dönel parçalar için optimum veya optimuma en yakın islem sıralamalarının, genetik algoritmaya dayalı herüstik arastırma tekniği kullanılarak belirlenmesidir. Bu amaç doğrultusunda, CAD paketinden bilgi çıkarımı, islenecek parçanın unsur bilgilerinin elde edilmesi, parça için mümkün olan tüm islem sıralarının belirlenmesi ve öncelik grafiğinin hazırlanması gibi modüller gelistirilmistir. Yapılan uygun bir islem sırası optimizasyonu ile kalem değistirme ve kalemin bosta gezme zamanı düsürülmekte ve buna bağlı olarak tezgahtan maksimum seviyede faydalanılmaktadır. Diğer bir ifade ile is parçasının üretim zamanı ve maliyeti önemli ölçüde düsürülmektedir.The use of CAD database saves a considerable amount of work and time to transform the design model represented in C...
Bu çalısmada, genetik algoritmalar yoluyla helis disli çarkların optimum modül seçimi yapılmıstır... more Bu çalısmada, genetik algoritmalar yoluyla helis disli çarkların optimum modül seçimi yapılmıstır. Belirlenen sınır aralıklarındaki değiskenler için amaç fonksiyonunun optimizasyonunu gerçeklestirmek, çalısmanın temel hedefi olmustur. Bu sekilde gelistirilmis olan algoritma, bir genetik süreç gibi en iyiyi bulma ilkesine dayandığından sınır aralıkları içinden değiskenlerin aldıkları değerler, dislinin optimum modüle sahip olmasını sağlayacaktır. Genetik Algoritmalar tabii seleksiyon fikrine dayalı arama uzayında oldukça etkili bir tarama tekniğidir. Yapılan çalısma yeni bir optimizasyon yöntemi olan genetik algoritma ile en uygun modül seçimi yapılabileceğini göstermektedir.In this paper, optimum module selection has been done using genetic algorithms. The main reason of the study is the identifying the variables of range of the module. The developed algorithm is based on the principle of finding optimal values like a genetic process, so the values from the limited range will make t...
Bu çalısmada, genetik algoritma ile optimum vidalı mil çapı seçimi yapılmıstır. Tasarımı yapılan ... more Bu çalısmada, genetik algoritma ile optimum vidalı mil çapı seçimi yapılmıstır. Tasarımı yapılan vidalı krikonun, belirlenen sınır aralıklardaki değiskenler için optimizasyonuna gidilmistir. Bu sekilde gelistirilmis olan algoritma, bir genetik süreç gibi en iyiyi bulma ilkesine dayandığından sınır aralıkları içinden değiskenlerin aldıkları değerler, vidalı krikonun optimum ebatlarda olmasını sağlayacaktır. Genetik algoritma, tabii seçim fikriyle çalısan, arama uzayında değiskenlerin sınır aralıkları için, amaç fonksiyonunu minimum yapmakta kullanılmıstır.In this paper, selection of optimum screw shaft diameter has been identified using genetic algorithm. The variables of screw shaft diameters have been optimized. The developed algorithm is based on the principle of finding optimal values like a genetic process, the values from the limited range will made the screw jack to have optimum dimensions. Genetic Algorithms for variables in a boundary space that are inspired from natural sel...
ABSTRACT Alumix 431 metal powders have been used in this study since they are widely used in the ... more ABSTRACT Alumix 431 metal powders have been used in this study since they are widely used in the industrial applications. First, Alumix 431 powders were compacted at 400 MPa pressure under room temperature (RT). Then, pressed specimens were sintered separately at 600 and 620°C for 1h N2. Densities were measured for the different temperatures in order to examine the effects of the sintering on density. Improvement of green density was observed to have enhanced approximately 86 and 90% according to theoretical density (2, 786 g/cm3) as a result of the sintering condition at 600 and 620°C, respectively. After sintering a group of specimen was shot peened with the intensities in 12 and 16A. To investigate mechanical properties of as sintered (unpeened) and shot peened samples, tensile and fatigue tests were performed. It was determined that shot peening improved the fatigue strength about 10 and 15% in 12 and 16A intensities, respectively. In addition, fractured specimens after tensile tests were used for Micro-Hardness measurements, and for metallographic analysis by, optical microscopy (OM) and scanning electron microscopy (SEM) tests further specimens were examined.Für diese Arbeit wurden die Metallpulver Alumix 431 ausgewählt, die in der industriellen Praxis häufig verwendet werden. Zuerst wurde das Metallpulver Alumix 431 bei einem Pressdruck 400 MPa unter Raumtemperatur kompaktiert. Danach wurden die gepressten Proben bei 600 und 620°C Temperatur jeweils 60 Minuten in N2-Atmospäre gesintert. Um die Auswirkung des Sinterns auf die Dichte zu beobachten, wurden bei unterschiedlichen Temperaturen hergestellte Proben untersucht. Nach der Kompaktierung wurden unter den Temperaturen 600 und 620°C 86% bzw. 90% der theoretischen Dichte erreicht. Dies zeigt, dass die gepresste Dichte durch das unterschiedliche Sinterlegierungsverhalten zunimmt. Nach der Sinterung wurde mit einer Intensität von 12A und 16A ein Teil der Proben kugelgestrahlt. Um die Eigenschaften der gestrahlten und nicht gestrahlten Proben zu untersuchen, wurden Ermüdungsfestigkeitsversuche durchgeführt. Das Kugelstrahlen erhöht die Ermüdungsfestigkeit etwa um 10 bis 15%. Außerdem wurden die nach dem Zugversuch erhaltenen Bruchstücke für Mikrohärtenmessungen verwendet. Die metallographischen Untersuchungen der Proben wurde im Licht-Mikroskop (OM) und Raster-Elektronenmikroskop (SEM) untersucht.
TEZ4078Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2001.Kaynakça (s. 90-99) var.x, 139 s... more TEZ4078Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2001.Kaynakça (s. 90-99) var.x, 139 s. ; 30 cm.
ABSTRACT The cold isostatic pressing behaviour of aluminium and iron powders was analysed, both e... more ABSTRACT The cold isostatic pressing behaviour of aluminium and iron powders was analysed, both experimentally using a cold isostatic pressing unit, and numerically using a nonlinear finite element program. The pressing unit, which can withstand up to 650 MPa pressure was designed and constructed in this study. Aluminium and iron powders, having different hardness values and almost the same particle sizes, have been pressed in the pressure unit and the mechanical behaviours of these powders were investigated in the 100-500 MPa pressure range. Attained densities were about 98% for aluminium and 88% for iron powders. Pressing resulted in significant increases in microhardnesses of the aluminium and iron powders. Light and scanning electron microscopy examinations revealed that severe plastic deformation took place in the powders of aluminium and iron. The densification behaviour of aluminium and iron powders under the cold isostatic pressing was also analysed using the finite element method, in which an elasto-plastic model was used to represent the powders. The relationship between the relative density of powder sample and applied pressure was predicted from finite element analysis and compared with the experimental data. A very good agreement between finite element results and experimental data was observed during the cold isostatic pressing.
TEZ6873Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2008.Kaynakça (s.119-133) var.xiv, 161 s. :... more TEZ6873Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2008.Kaynakça (s.119-133) var.xiv, 161 s. : rnk.res. ; 29 cm.Introducing new products at ever increasing rates is important for remaining successful in a competitive global economy; decreasing product development cycle times and increasing product complexity require new ways to take in novel ideas. During the last decades, a new concept called Rapid Prototyping (RP), Layered Manufacturing (LM) has gained popularity in Turkey and worldwide especially in the area of product development, prototyping and tooling. The goal of Rapid Prototyping (RP) is to be able to quickly fabricate complex-shaped, threedimensional parts directly from Computer Aided Design (CAD) models. The aim of this study is to fabricate parts with minimum time and high surface quality using direct CAD based uniform and adaptive slicing algorithm in Fused Deposition Modelling (FDM) process. As an input, Non Uniform Rational B- Splines (NURBS) based model is used wh...
The methodology of Acoustic Emission (AE) for detecting and monitoring damages, cracks and leaks ... more The methodology of Acoustic Emission (AE) for detecting and monitoring damages, cracks and leaks in different structures is widely used and has earned a reputation recently as one of the most reliable and wellestablished technique in Non-Destructive Testing (NDT). Besides evaluation of fracture behavior, crack propagation and fatigue detection in metals, composites, wood, fiberglass, ceramics and plastics; it can also be used for detecting faults and pressure leaks in pressure vessels, tanks and pipes. As a relatively "clean" form of energy, Liquefied Petroleum Gas (LPG) is widely used for industrial applications and domestic heating. Periodic inspection of buried tanks used for LPG storage is complicated and limited because of their underground location. This situation prevents "conventional" NDT techniques from being used. So, AE testing which fulfills all safety requirements, is the most appropriate and cost-effective technique that can be used for periodic inspection and proof testing. In addition of a general presentation on the AE technology and its applications, this study provides comprehensive evaluation of AE testing techniques of underground LPG tanks during service in accordance with TS EN standards. Some representative results and data obtained from a performed AE test are also provided.
In this study, Reliability Centered Maintenance (RCM) approach and Failure Mode and Effect Analys... more In this study, Reliability Centered Maintenance (RCM) approach and Failure Mode and Effect Analysis (FMEA) are used for hydraulic driven injection molding machine to evaluate the reliability of components as well as to identify the technical risk levels. In order to minimize these risk levels, RCM tasks and time periods of maintenance tasks are developed. Also, high risky failure modes are elaborated in the related FMEA sections of components to develop troubleshooting keys and innovative solutions by using visual, functional and metallurgical examination methods in terms of mechanical engineering approach. FMEA of hydraulic oil is only detailed presented in this article because of the effect on the all possible failures of the other hydraulic system equipment. Achieved scores of productivity rates which have been provided by FMEA of all components are discussed at the end of the study.
... Bu amaçla, KÜ teknolojisindeki bilgi gereksinmeleri ve hali haz rda kullan lan ve ara tr lan ... more ... Bu amaçla, KÜ teknolojisindeki bilgi gereksinmeleri ve hali haz rda kullan lan ve ara tr lan bilgi transfer protokolleri incelenmi ve yeni bir bilgi transfer format ihtiyac belirlenmi tir. Anahtar Kelimeler : Katmanl Üretim, H zl Prototipleme, KÜ, bilgi transferi, stl. ...
Bilgisayar destekli tasarım verilerinin kullanımı, CAD içerisindeki tasarım modelinin islem planl... more Bilgisayar destekli tasarım verilerinin kullanımı, CAD içerisindeki tasarım modelinin islem planlaması için unsur modeline dönüstürülmesi asamasında önemli ölçüde is ve zaman tasarrufu sağlamaktadır. Bu çalısmada amaçlanan, dönel parçalar için optimum veya optimuma en yakın islem sıralamalarının, genetik algoritmaya dayalı herüstik arastırma tekniği kullanılarak belirlenmesidir. Bu amaç doğrultusunda, CAD paketinden bilgi çıkarımı, islenecek parçanın unsur bilgilerinin elde edilmesi, parça için mümkün olan tüm islem sıralarının belirlenmesi ve öncelik grafiğinin hazırlanması gibi modüller gelistirilmistir. Yapılan uygun bir islem sırası optimizasyonu ile kalem değistirme ve kalemin bosta gezme zamanı düsürülmekte ve buna bağlı olarak tezgahtan maksimum seviyede faydalanılmaktadır. Diğer bir ifade ile is parçasının üretim zamanı ve maliyeti önemli ölçüde düsürülmektedir.The use of CAD database saves a considerable amount of work and time to transform the design model represented in C...
Bu çalısmada, genetik algoritmalar yoluyla helis disli çarkların optimum modül seçimi yapılmıstır... more Bu çalısmada, genetik algoritmalar yoluyla helis disli çarkların optimum modül seçimi yapılmıstır. Belirlenen sınır aralıklarındaki değiskenler için amaç fonksiyonunun optimizasyonunu gerçeklestirmek, çalısmanın temel hedefi olmustur. Bu sekilde gelistirilmis olan algoritma, bir genetik süreç gibi en iyiyi bulma ilkesine dayandığından sınır aralıkları içinden değiskenlerin aldıkları değerler, dislinin optimum modüle sahip olmasını sağlayacaktır. Genetik Algoritmalar tabii seleksiyon fikrine dayalı arama uzayında oldukça etkili bir tarama tekniğidir. Yapılan çalısma yeni bir optimizasyon yöntemi olan genetik algoritma ile en uygun modül seçimi yapılabileceğini göstermektedir.In this paper, optimum module selection has been done using genetic algorithms. The main reason of the study is the identifying the variables of range of the module. The developed algorithm is based on the principle of finding optimal values like a genetic process, so the values from the limited range will make t...
Bu çalısmada, genetik algoritma ile optimum vidalı mil çapı seçimi yapılmıstır. Tasarımı yapılan ... more Bu çalısmada, genetik algoritma ile optimum vidalı mil çapı seçimi yapılmıstır. Tasarımı yapılan vidalı krikonun, belirlenen sınır aralıklardaki değiskenler için optimizasyonuna gidilmistir. Bu sekilde gelistirilmis olan algoritma, bir genetik süreç gibi en iyiyi bulma ilkesine dayandığından sınır aralıkları içinden değiskenlerin aldıkları değerler, vidalı krikonun optimum ebatlarda olmasını sağlayacaktır. Genetik algoritma, tabii seçim fikriyle çalısan, arama uzayında değiskenlerin sınır aralıkları için, amaç fonksiyonunu minimum yapmakta kullanılmıstır.In this paper, selection of optimum screw shaft diameter has been identified using genetic algorithm. The variables of screw shaft diameters have been optimized. The developed algorithm is based on the principle of finding optimal values like a genetic process, the values from the limited range will made the screw jack to have optimum dimensions. Genetic Algorithms for variables in a boundary space that are inspired from natural sel...
ABSTRACT Alumix 431 metal powders have been used in this study since they are widely used in the ... more ABSTRACT Alumix 431 metal powders have been used in this study since they are widely used in the industrial applications. First, Alumix 431 powders were compacted at 400 MPa pressure under room temperature (RT). Then, pressed specimens were sintered separately at 600 and 620°C for 1h N2. Densities were measured for the different temperatures in order to examine the effects of the sintering on density. Improvement of green density was observed to have enhanced approximately 86 and 90% according to theoretical density (2, 786 g/cm3) as a result of the sintering condition at 600 and 620°C, respectively. After sintering a group of specimen was shot peened with the intensities in 12 and 16A. To investigate mechanical properties of as sintered (unpeened) and shot peened samples, tensile and fatigue tests were performed. It was determined that shot peening improved the fatigue strength about 10 and 15% in 12 and 16A intensities, respectively. In addition, fractured specimens after tensile tests were used for Micro-Hardness measurements, and for metallographic analysis by, optical microscopy (OM) and scanning electron microscopy (SEM) tests further specimens were examined.Für diese Arbeit wurden die Metallpulver Alumix 431 ausgewählt, die in der industriellen Praxis häufig verwendet werden. Zuerst wurde das Metallpulver Alumix 431 bei einem Pressdruck 400 MPa unter Raumtemperatur kompaktiert. Danach wurden die gepressten Proben bei 600 und 620°C Temperatur jeweils 60 Minuten in N2-Atmospäre gesintert. Um die Auswirkung des Sinterns auf die Dichte zu beobachten, wurden bei unterschiedlichen Temperaturen hergestellte Proben untersucht. Nach der Kompaktierung wurden unter den Temperaturen 600 und 620°C 86% bzw. 90% der theoretischen Dichte erreicht. Dies zeigt, dass die gepresste Dichte durch das unterschiedliche Sinterlegierungsverhalten zunimmt. Nach der Sinterung wurde mit einer Intensität von 12A und 16A ein Teil der Proben kugelgestrahlt. Um die Eigenschaften der gestrahlten und nicht gestrahlten Proben zu untersuchen, wurden Ermüdungsfestigkeitsversuche durchgeführt. Das Kugelstrahlen erhöht die Ermüdungsfestigkeit etwa um 10 bis 15%. Außerdem wurden die nach dem Zugversuch erhaltenen Bruchstücke für Mikrohärtenmessungen verwendet. Die metallographischen Untersuchungen der Proben wurde im Licht-Mikroskop (OM) und Raster-Elektronenmikroskop (SEM) untersucht.
TEZ4078Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2001.Kaynakça (s. 90-99) var.x, 139 s... more TEZ4078Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2001.Kaynakça (s. 90-99) var.x, 139 s. ; 30 cm.
ABSTRACT The cold isostatic pressing behaviour of aluminium and iron powders was analysed, both e... more ABSTRACT The cold isostatic pressing behaviour of aluminium and iron powders was analysed, both experimentally using a cold isostatic pressing unit, and numerically using a nonlinear finite element program. The pressing unit, which can withstand up to 650 MPa pressure was designed and constructed in this study. Aluminium and iron powders, having different hardness values and almost the same particle sizes, have been pressed in the pressure unit and the mechanical behaviours of these powders were investigated in the 100-500 MPa pressure range. Attained densities were about 98% for aluminium and 88% for iron powders. Pressing resulted in significant increases in microhardnesses of the aluminium and iron powders. Light and scanning electron microscopy examinations revealed that severe plastic deformation took place in the powders of aluminium and iron. The densification behaviour of aluminium and iron powders under the cold isostatic pressing was also analysed using the finite element method, in which an elasto-plastic model was used to represent the powders. The relationship between the relative density of powder sample and applied pressure was predicted from finite element analysis and compared with the experimental data. A very good agreement between finite element results and experimental data was observed during the cold isostatic pressing.
TEZ6873Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2008.Kaynakça (s.119-133) var.xiv, 161 s. :... more TEZ6873Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2008.Kaynakça (s.119-133) var.xiv, 161 s. : rnk.res. ; 29 cm.Introducing new products at ever increasing rates is important for remaining successful in a competitive global economy; decreasing product development cycle times and increasing product complexity require new ways to take in novel ideas. During the last decades, a new concept called Rapid Prototyping (RP), Layered Manufacturing (LM) has gained popularity in Turkey and worldwide especially in the area of product development, prototyping and tooling. The goal of Rapid Prototyping (RP) is to be able to quickly fabricate complex-shaped, threedimensional parts directly from Computer Aided Design (CAD) models. The aim of this study is to fabricate parts with minimum time and high surface quality using direct CAD based uniform and adaptive slicing algorithm in Fused Deposition Modelling (FDM) process. As an input, Non Uniform Rational B- Splines (NURBS) based model is used wh...
The methodology of Acoustic Emission (AE) for detecting and monitoring damages, cracks and leaks ... more The methodology of Acoustic Emission (AE) for detecting and monitoring damages, cracks and leaks in different structures is widely used and has earned a reputation recently as one of the most reliable and wellestablished technique in Non-Destructive Testing (NDT). Besides evaluation of fracture behavior, crack propagation and fatigue detection in metals, composites, wood, fiberglass, ceramics and plastics; it can also be used for detecting faults and pressure leaks in pressure vessels, tanks and pipes. As a relatively "clean" form of energy, Liquefied Petroleum Gas (LPG) is widely used for industrial applications and domestic heating. Periodic inspection of buried tanks used for LPG storage is complicated and limited because of their underground location. This situation prevents "conventional" NDT techniques from being used. So, AE testing which fulfills all safety requirements, is the most appropriate and cost-effective technique that can be used for periodic inspection and proof testing. In addition of a general presentation on the AE technology and its applications, this study provides comprehensive evaluation of AE testing techniques of underground LPG tanks during service in accordance with TS EN standards. Some representative results and data obtained from a performed AE test are also provided.
In this study, Reliability Centered Maintenance (RCM) approach and Failure Mode and Effect Analys... more In this study, Reliability Centered Maintenance (RCM) approach and Failure Mode and Effect Analysis (FMEA) are used for hydraulic driven injection molding machine to evaluate the reliability of components as well as to identify the technical risk levels. In order to minimize these risk levels, RCM tasks and time periods of maintenance tasks are developed. Also, high risky failure modes are elaborated in the related FMEA sections of components to develop troubleshooting keys and innovative solutions by using visual, functional and metallurgical examination methods in terms of mechanical engineering approach. FMEA of hydraulic oil is only detailed presented in this article because of the effect on the all possible failures of the other hydraulic system equipment. Achieved scores of productivity rates which have been provided by FMEA of all components are discussed at the end of the study.
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