2016 7th International Conference on Mechanical and Aerospace Engineering (ICMAE), 2016
Multi Particle Finite Element Method (MPFEM) which is a power full approach for particle systems ... more Multi Particle Finite Element Method (MPFEM) which is a power full approach for particle systems analyzes particle interactions via different friction models. In this study, Amontons-Coulomb constant friction (ACM), Wanheim/Bay generalized friction (WBM) and Levanov's friction models (LFM) are utilized in MPFEM in order to obtain coefficient of friction at particle-particle and particle-die wall interactions in spherical copper powder compaction. Friction models are introduced into the analysis by user subroutines. Compaction processes at room temperature and at 270°C were investigated by terms of coefficient of friction, shear stress and equivalent strain. Although equivalent strain curve of WBM and LFM are in good agreement, ACM resulted in higher equivalent strain and shear stress values. Coefficient of friction those were obtained with WBM and LFM varies in a reasonable range.
Many metal forming processes can be simulated by using the Physical Modeling Technique which requ... more Many metal forming processes can be simulated by using the Physical Modeling Technique which requires an inexpensive and small amount of apparatus. The underlying principle behind the Physical Modeling Technique is to simulate the actual metal forming process by selecting a model material and die geometry that closely resemble the actual metal forming process. Typical modeling materials are PLASTICINE, wax and lead while the typical die models are usually made of aluminum, wood or plexiglass. In two-dimensional analyses, a square or circular grid pattern is printed on the surface of the specimen using ink and a grid stencil. The common method of generating the grid pattern is to use different types of PLASTICINE instead of using ink. Therefore, alternating slabs of PLASTICINE of different colors automatically form the grid patterns. In the first phase of this study, 16 types of PLASTICINE were tested, via standard compression tests, in order to determine their flow behavior and to i...
IOP Conference Series: Materials Science and Engineering, 2018
9th International Conference on Tribology (Balkantrib) -- SEP 13-15, 2017 -- TURKEYguner, faruk/0... more 9th International Conference on Tribology (Balkantrib) -- SEP 13-15, 2017 -- TURKEYguner, faruk/0000-0002-3438-0553; SOFUOGLU, HASAN/0000-0002-8433-4045WOS: 000448617300027Powder metallurgy (PM) has been widely used in several industries; especially automotive and aerospace industries and powder metallurgy products grow up every year. The mechanical properties of the final product that is obtained by cold compaction and sintering in powder metallurgy are closely related to the final relative density of the process. The distribution of the relative density in the die is affected by parameters such as compaction velocity, friction coefficient and temperature. Moreover, most of the numerical studies utilizing finite element approaches treat the examined environment as a continuous media with uniformly homogeneous porosity whereas Multi-Particle Finite Element Method (MPFEM) treats every particles as an individual body. In MPFEM, each of the particles can be defined as an elastic-plastic deformable body, so the interactions of the particles with each other and the die wall can be investigated. In this study, each particle was modelled and analyzed as individual deformable body with 3D tetrahedral elements by using MPFEM approach. This study, therefore, was performed to investigate the effects of different temperatures and compaction velocities on stress distribution and deformations of copper powders of 200 mu m-diameter in compaction process. Furthermore, 3-D MPFEM model utilized von Mises material model and constant coefficient of friction of mu=0.05. In addition to MPFEM approach, continuum modelling approach was also performed for comparison purposes.Petroyag Lubricants, UCTEA, TMMO
Solid particle erosion behavior of AA 6061 aluminum alloy was evaluated using a recently develope... more Solid particle erosion behavior of AA 6061 aluminum alloy was evaluated using a recently developed erosion wear test system. Wear tests were performed under different impact angles (20°, 30°, 45°, 60°, 90°) and velocities (74, 90, 150, 195 m/s) at ambient temperature. Alumina particles with 50 μm in dimension were used as erodent. Results showed that higher the impact velocity the higher the erosion rate is obtained. On the other hand, the highest erosion rate was recorded for the impact angle of 20°. Optical microscopy images revealed that several mechanisms such as plastic deformation and scratching involved in erosion behavior. INTRODUCTION Solid particle erosion is one of the major reasons leading large financial losses and service interruptions in aviation industry. Gas turbines blades, fuel tanks, ammunition, compressors of helicopters and aircrafts are among the components affected by solid particle erosion. A structural part called erosion shield is used to minimize erosion ...
Australasian physical & engineering sciences in medicine, 2018
This study was carried out to determine mechanical behavior and bone adaptation of total hip arth... more This study was carried out to determine mechanical behavior and bone adaptation of total hip arthroplasty (THA) subject to concentrated and distributed muscle loads and hip contact forces during activities of walking and stair climbing. Finite element modeling of THA with different prostheses, activity and loading types was developed by adopting a statistical method. Two levels of prostheses, activity, and loading types were selected for the study. 2 factorial method was then pursued to design input and output data of finite element analysis. Maximum von Mises stresses were chosen to be output data on which statistical investigation was performed to investigate contribution and interaction of main factors on mechanical failure of cemented THA reconstructions by utilizing analysis of variance method (ANOVA). This study illustrated that the maximum von Mises stresses of THA showed considerable variation for main factors and their two-factor interactions.
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada, ilk olarak Zn-22Al alaşımı uygulanan aşırı plastik deformasyon (APD) yöntemi ile ultra-ince tane (UİT) yapılı (Tane boyutu: 200nm) hale getirildi. Daha sonra oluşturulan bu yapının tek ve iki eksenli gerilme altındaki şekillendirilebilirlik davranışı deneysel ve sayısal olarak analiz edildi. İki eksenli gerilme altında analiz için minyatürüze edilmiş Erichsen testi, sayısal analiz için ise Ls-Dyna sonlu elemanlar yazılımı kullanıldı. Tek eksenli çekme testi sonrası yüksek deformasyon hızlarında (10-1 s-1) yaklaşık %340 kopma uzaması ve 225 MPa’lık akma gerilmesi elde edildi. Söz konusu deformasyon hızında yaklaşık 5.30 mm’lik bir Erichsen indeksi (Ei) elde edildi. Bu çalışmalar sonunda, süperplastik Zn-22Al alaşımı için bütün deformasyon hızlarında tek eksenli ve iki eksenli şekillendirilebilirlik açısından ...
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2011Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2011Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2011Biyomekanik, biyoloji ve mühendislik bilimlerinin yaşayan canlılar üzerindeki uygulama alanı olup soıı yıllarda dünyada popüler hale gelen bir bilim dalı olmuştur. Biyomekaniğin günümüzde en fazla ilgi gören konularından birisi de insan kafasıdır. İnsan kafası, birçok biyolojik dokuyu içermektedir. Örneğin beyin, beyincik, zarlar, beyin omurilik sıvısı, damarlar, beyin sapı vb. Bu çalışmada, insan kafasını oluşturan beyin, kafatası ve deriyi kapsayan 3 boyutlu bir insan kafasının sonlu elemanlar yöntemiyle analizi yapılmıştır. Model oluşturulduktan sonra insan kafası ve beyninin sabit statik yük altındaki davranışı, kafanın frontal bölgesine, 6000 N olacak şekilde bir yük uygulanarak incelenmiş olup elde edilen bulgular sunulmuştur. Analiz sonucunda von Mises gerilme dağılımı her doku için ııyıı ayrı belirlenmiştir. Ayrıc...
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada nümune boyut etkisi ve sürtünme katsayısının bir mikro derin çekme parçasının şekillendirilmesine etkisi sonlu eleman analizi yardımıyla incelenmiştir. Boyut etkisini incelemek amacıyla 0.1 , 0.2 ve 1 mm kalınlıklarında 3 farklı sac kullanılmış; kalıp ve zımbaya ait ölçüler de her bir işlemde aynı oranda arttırılarak 3 farklı sonlu eleman modeli oluşturulmuştur. Sac kalınlığının azaltılmasıyla eşdeğer von Mises gerilmesi değerlerinin arttığı tespit edilmiştir. Tribolojik boyut etkisinin belirlenmesi amacıyla yapılan analizlerde ise sürtünme katsayısının arttırılması durumunda eşdeğer gerilmelerde artış gözlenmiş ve 0.1 mm sac kalınlığı için en yüksek eşdeğer gerilme değeri elde edilmiştir.Effects of specimen size and coefficient of friction on micro-deep drawn part have been investigated by means of finite el...
Bu çalışmada nümune boyut etkisi ve sürtünme katsayısının bir mikro derin çekme parçasının şekill... more Bu çalışmada nümune boyut etkisi ve sürtünme katsayısının bir mikro derin çekme parçasının şekillendirilmesine etkisi sonlu eleman analizi yardımıyla incelenmiştir. Boyut etkisini incelemek amacıyla 0.1 , 0.2 ve 1 mm kalınlıklarında 3 farklı sac kullanılmış; kalıp ve zımbaya ait ölçüler de her bir işlemde aynı oranda arttırılarak 3 farklı sonlu eleman modeli oluşturulmuştur. Sac kalınlığının azaltılmasıyla eşdeğer von Mises gerilmesi değerlerinin arttığı tespit edilmiştir. Tribolojik boyut etkisinin belirlenmesi amacıyla yapılan analizlerde ise sürtünme katsayısının arttırılması durumunda eşdeğer gerilmelerde artış gözlenmiş ve 0.1 mm sac kalınlığı için en yüksek eşdeğer gerilme değeri elde edilmiştir.Effects of specimen size and coefficient of friction on micro-deep drawn part have been investigated by means of finite element analysis. To this goal, blanks with three different thicknesses, namely 0.1, 0.2, and 1 mm, have been used. Furthermore, dimensions for die and punch are incr...
Micro fabrication techniques used for the production of dental implants offer different surface s... more Micro fabrication techniques used for the production of dental implants offer different surface shaping options particularly effective on the quality of osseointegration. However, to obtain osseointegration with current implant surface roughening techniques bring about various problems. These are mainly operating and maintenance costs of systems used in roughening process, high cost of powder used in blasting, being an imported material, health risk due to blasting powder, high noise at production area and adverse effects of chemicals used. The purpose of this study is to determine the stress values of dental implants with micro-scale hemispherical pockets on the surface produced at CNC machines under various loading conditions after osseointegration. In the study, solid modelling programs were used to design dental implant. Hemispherical cavities in the diameter of 150 and 300 µm are opened on the surface of dental implants excluding the grooved surfaces. Loadings were carried out ...
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2008Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2008Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2008Bu çalışmada, yüzey pürüzlülüğünün temas basıncı, şekil değiştirme ve gerilmeler üzerindeki etkilerini araştırmak amacıyla; pürüzlü yüzey ile yarı-sonsuz ortamın temas analizi sonlu elemanlar yöntemiyle gerçekleştirilmiştir. Bu amaçla, fraktal geometri ile modellenmiş rijit pürüzlü yüzeyin homojen, elastik-tam plastik pürüzsüz yarı-sonsuz ortam ile normal teması için 2-boyutlu bir sonlu elemanlar modeli geliştirilmiştir. Mekanik yüzey yüklerinin yarısonsuz ortamda oluşan von Mises eşdeğer gerilmesi, elastik-plastik şekil değiştirmeleri ile temas basınç değerleri üzerindeki etkileri belirlenmiştir. Ayrıca, rijit pürüzlü yüzeyin yarısonsuz ortam içindeki temas derinliği miktarının (girişim) şekil değişimine etkisi de incelenmiştir. Fraktal geometri kullanarak geliştirilen ve böylece pürüz etkileşimlerinin de dikkate alındığ...
Dental deficiency problems on the damaged mandibles can be solved by applying implant abutment wi... more Dental deficiency problems on the damaged mandibles can be solved by applying implant abutment with different lengths, artificial chin material and using prosthesis filling materials. The purpose of this study to investigate the stresses occurred on hard and soft bones after recovering the deficiency caused by totally edentulous and damaged mandible by using abutments with different lengths and prosthesis filling material. At the first step of this study, prosthesis data were obtained by optical scanning method. The data were then used to design an implant model suited to prosthesis using Solidwork programs. Later, 3-D model of assembly with abutment and mandible (soft bone, hard bone and mucosa) was created. Two different damaged parts of 2.5 and 4.5 mm in depth were created with the aid of Solidwork program on the right hand side of the mandible. Implants were then applied between the foremen channels. Later, the damaged models were recovered by abutment with different lengths as ...
Journal of Engineering Materials and Technology, 2019
This study aimed to investigate the micro deep drawability of Zn-22Al alloy at room temperature i... more This study aimed to investigate the micro deep drawability of Zn-22Al alloy at room temperature in which it shows superplastic properties. To this goal, two-step equal channel angular extrusion (ECAE) process was carried out to obtain an ultra-fine grained structure (UFG), first. Upon achieving the grain size of 200 nm, the formability of the alloy at room temperature and at a high strain rate was investigated both experimentally and numerically. Micro deep drawing experiments were performed at different deep drawing ratios (1.66, 1.84, 2.0 and 2.25) and for different sheet thicknesses (0.2, 0.4 and 0.6 mm). Finite element model of the micro deep drawing was also established to assess and compare the thickness variation in deep drawn parts. Results showed that the superplastic Zn-22Al alloy has a great potential in microforming applications. It was also noted that the limiting drawing ratio can be obtained as high as 2.25 in room temperature condition.
2016 7th International Conference on Mechanical and Aerospace Engineering (ICMAE), 2016
Multi Particle Finite Element Method (MPFEM) which is a power full approach for particle systems ... more Multi Particle Finite Element Method (MPFEM) which is a power full approach for particle systems analyzes particle interactions via different friction models. In this study, Amontons-Coulomb constant friction (ACM), Wanheim/Bay generalized friction (WBM) and Levanov's friction models (LFM) are utilized in MPFEM in order to obtain coefficient of friction at particle-particle and particle-die wall interactions in spherical copper powder compaction. Friction models are introduced into the analysis by user subroutines. Compaction processes at room temperature and at 270°C were investigated by terms of coefficient of friction, shear stress and equivalent strain. Although equivalent strain curve of WBM and LFM are in good agreement, ACM resulted in higher equivalent strain and shear stress values. Coefficient of friction those were obtained with WBM and LFM varies in a reasonable range.
Many metal forming processes can be simulated by using the Physical Modeling Technique which requ... more Many metal forming processes can be simulated by using the Physical Modeling Technique which requires an inexpensive and small amount of apparatus. The underlying principle behind the Physical Modeling Technique is to simulate the actual metal forming process by selecting a model material and die geometry that closely resemble the actual metal forming process. Typical modeling materials are PLASTICINE, wax and lead while the typical die models are usually made of aluminum, wood or plexiglass. In two-dimensional analyses, a square or circular grid pattern is printed on the surface of the specimen using ink and a grid stencil. The common method of generating the grid pattern is to use different types of PLASTICINE instead of using ink. Therefore, alternating slabs of PLASTICINE of different colors automatically form the grid patterns. In the first phase of this study, 16 types of PLASTICINE were tested, via standard compression tests, in order to determine their flow behavior and to i...
IOP Conference Series: Materials Science and Engineering, 2018
9th International Conference on Tribology (Balkantrib) -- SEP 13-15, 2017 -- TURKEYguner, faruk/0... more 9th International Conference on Tribology (Balkantrib) -- SEP 13-15, 2017 -- TURKEYguner, faruk/0000-0002-3438-0553; SOFUOGLU, HASAN/0000-0002-8433-4045WOS: 000448617300027Powder metallurgy (PM) has been widely used in several industries; especially automotive and aerospace industries and powder metallurgy products grow up every year. The mechanical properties of the final product that is obtained by cold compaction and sintering in powder metallurgy are closely related to the final relative density of the process. The distribution of the relative density in the die is affected by parameters such as compaction velocity, friction coefficient and temperature. Moreover, most of the numerical studies utilizing finite element approaches treat the examined environment as a continuous media with uniformly homogeneous porosity whereas Multi-Particle Finite Element Method (MPFEM) treats every particles as an individual body. In MPFEM, each of the particles can be defined as an elastic-plastic deformable body, so the interactions of the particles with each other and the die wall can be investigated. In this study, each particle was modelled and analyzed as individual deformable body with 3D tetrahedral elements by using MPFEM approach. This study, therefore, was performed to investigate the effects of different temperatures and compaction velocities on stress distribution and deformations of copper powders of 200 mu m-diameter in compaction process. Furthermore, 3-D MPFEM model utilized von Mises material model and constant coefficient of friction of mu=0.05. In addition to MPFEM approach, continuum modelling approach was also performed for comparison purposes.Petroyag Lubricants, UCTEA, TMMO
Solid particle erosion behavior of AA 6061 aluminum alloy was evaluated using a recently develope... more Solid particle erosion behavior of AA 6061 aluminum alloy was evaluated using a recently developed erosion wear test system. Wear tests were performed under different impact angles (20°, 30°, 45°, 60°, 90°) and velocities (74, 90, 150, 195 m/s) at ambient temperature. Alumina particles with 50 μm in dimension were used as erodent. Results showed that higher the impact velocity the higher the erosion rate is obtained. On the other hand, the highest erosion rate was recorded for the impact angle of 20°. Optical microscopy images revealed that several mechanisms such as plastic deformation and scratching involved in erosion behavior. INTRODUCTION Solid particle erosion is one of the major reasons leading large financial losses and service interruptions in aviation industry. Gas turbines blades, fuel tanks, ammunition, compressors of helicopters and aircrafts are among the components affected by solid particle erosion. A structural part called erosion shield is used to minimize erosion ...
Australasian physical & engineering sciences in medicine, 2018
This study was carried out to determine mechanical behavior and bone adaptation of total hip arth... more This study was carried out to determine mechanical behavior and bone adaptation of total hip arthroplasty (THA) subject to concentrated and distributed muscle loads and hip contact forces during activities of walking and stair climbing. Finite element modeling of THA with different prostheses, activity and loading types was developed by adopting a statistical method. Two levels of prostheses, activity, and loading types were selected for the study. 2 factorial method was then pursued to design input and output data of finite element analysis. Maximum von Mises stresses were chosen to be output data on which statistical investigation was performed to investigate contribution and interaction of main factors on mechanical failure of cemented THA reconstructions by utilizing analysis of variance method (ANOVA). This study illustrated that the maximum von Mises stresses of THA showed considerable variation for main factors and their two-factor interactions.
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada, ilk olarak Zn-22Al alaşımı uygulanan aşırı plastik deformasyon (APD) yöntemi ile ultra-ince tane (UİT) yapılı (Tane boyutu: 200nm) hale getirildi. Daha sonra oluşturulan bu yapının tek ve iki eksenli gerilme altındaki şekillendirilebilirlik davranışı deneysel ve sayısal olarak analiz edildi. İki eksenli gerilme altında analiz için minyatürüze edilmiş Erichsen testi, sayısal analiz için ise Ls-Dyna sonlu elemanlar yazılımı kullanıldı. Tek eksenli çekme testi sonrası yüksek deformasyon hızlarında (10-1 s-1) yaklaşık %340 kopma uzaması ve 225 MPa’lık akma gerilmesi elde edildi. Söz konusu deformasyon hızında yaklaşık 5.30 mm’lik bir Erichsen indeksi (Ei) elde edildi. Bu çalışmalar sonunda, süperplastik Zn-22Al alaşımı için bütün deformasyon hızlarında tek eksenli ve iki eksenli şekillendirilebilirlik açısından ...
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2011Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2011Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2011Biyomekanik, biyoloji ve mühendislik bilimlerinin yaşayan canlılar üzerindeki uygulama alanı olup soıı yıllarda dünyada popüler hale gelen bir bilim dalı olmuştur. Biyomekaniğin günümüzde en fazla ilgi gören konularından birisi de insan kafasıdır. İnsan kafası, birçok biyolojik dokuyu içermektedir. Örneğin beyin, beyincik, zarlar, beyin omurilik sıvısı, damarlar, beyin sapı vb. Bu çalışmada, insan kafasını oluşturan beyin, kafatası ve deriyi kapsayan 3 boyutlu bir insan kafasının sonlu elemanlar yöntemiyle analizi yapılmıştır. Model oluşturulduktan sonra insan kafası ve beyninin sabit statik yük altındaki davranışı, kafanın frontal bölgesine, 6000 N olacak şekilde bir yük uygulanarak incelenmiş olup elde edilen bulgular sunulmuştur. Analiz sonucunda von Mises gerilme dağılımı her doku için ııyıı ayrı belirlenmiştir. Ayrıc...
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada nümune boyut etkisi ve sürtünme katsayısının bir mikro derin çekme parçasının şekillendirilmesine etkisi sonlu eleman analizi yardımıyla incelenmiştir. Boyut etkisini incelemek amacıyla 0.1 , 0.2 ve 1 mm kalınlıklarında 3 farklı sac kullanılmış; kalıp ve zımbaya ait ölçüler de her bir işlemde aynı oranda arttırılarak 3 farklı sonlu eleman modeli oluşturulmuştur. Sac kalınlığının azaltılmasıyla eşdeğer von Mises gerilmesi değerlerinin arttığı tespit edilmiştir. Tribolojik boyut etkisinin belirlenmesi amacıyla yapılan analizlerde ise sürtünme katsayısının arttırılması durumunda eşdeğer gerilmelerde artış gözlenmiş ve 0.1 mm sac kalınlığı için en yüksek eşdeğer gerilme değeri elde edilmiştir.Effects of specimen size and coefficient of friction on micro-deep drawn part have been investigated by means of finite el...
Bu çalışmada nümune boyut etkisi ve sürtünme katsayısının bir mikro derin çekme parçasının şekill... more Bu çalışmada nümune boyut etkisi ve sürtünme katsayısının bir mikro derin çekme parçasının şekillendirilmesine etkisi sonlu eleman analizi yardımıyla incelenmiştir. Boyut etkisini incelemek amacıyla 0.1 , 0.2 ve 1 mm kalınlıklarında 3 farklı sac kullanılmış; kalıp ve zımbaya ait ölçüler de her bir işlemde aynı oranda arttırılarak 3 farklı sonlu eleman modeli oluşturulmuştur. Sac kalınlığının azaltılmasıyla eşdeğer von Mises gerilmesi değerlerinin arttığı tespit edilmiştir. Tribolojik boyut etkisinin belirlenmesi amacıyla yapılan analizlerde ise sürtünme katsayısının arttırılması durumunda eşdeğer gerilmelerde artış gözlenmiş ve 0.1 mm sac kalınlığı için en yüksek eşdeğer gerilme değeri elde edilmiştir.Effects of specimen size and coefficient of friction on micro-deep drawn part have been investigated by means of finite element analysis. To this goal, blanks with three different thicknesses, namely 0.1, 0.2, and 1 mm, have been used. Furthermore, dimensions for die and punch are incr...
Micro fabrication techniques used for the production of dental implants offer different surface s... more Micro fabrication techniques used for the production of dental implants offer different surface shaping options particularly effective on the quality of osseointegration. However, to obtain osseointegration with current implant surface roughening techniques bring about various problems. These are mainly operating and maintenance costs of systems used in roughening process, high cost of powder used in blasting, being an imported material, health risk due to blasting powder, high noise at production area and adverse effects of chemicals used. The purpose of this study is to determine the stress values of dental implants with micro-scale hemispherical pockets on the surface produced at CNC machines under various loading conditions after osseointegration. In the study, solid modelling programs were used to design dental implant. Hemispherical cavities in the diameter of 150 and 300 µm are opened on the surface of dental implants excluding the grooved surfaces. Loadings were carried out ...
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2008Conference Paper -- ... more Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2008Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2008Bu çalışmada, yüzey pürüzlülüğünün temas basıncı, şekil değiştirme ve gerilmeler üzerindeki etkilerini araştırmak amacıyla; pürüzlü yüzey ile yarı-sonsuz ortamın temas analizi sonlu elemanlar yöntemiyle gerçekleştirilmiştir. Bu amaçla, fraktal geometri ile modellenmiş rijit pürüzlü yüzeyin homojen, elastik-tam plastik pürüzsüz yarı-sonsuz ortam ile normal teması için 2-boyutlu bir sonlu elemanlar modeli geliştirilmiştir. Mekanik yüzey yüklerinin yarısonsuz ortamda oluşan von Mises eşdeğer gerilmesi, elastik-plastik şekil değiştirmeleri ile temas basınç değerleri üzerindeki etkileri belirlenmiştir. Ayrıca, rijit pürüzlü yüzeyin yarısonsuz ortam içindeki temas derinliği miktarının (girişim) şekil değişimine etkisi de incelenmiştir. Fraktal geometri kullanarak geliştirilen ve böylece pürüz etkileşimlerinin de dikkate alındığ...
Dental deficiency problems on the damaged mandibles can be solved by applying implant abutment wi... more Dental deficiency problems on the damaged mandibles can be solved by applying implant abutment with different lengths, artificial chin material and using prosthesis filling materials. The purpose of this study to investigate the stresses occurred on hard and soft bones after recovering the deficiency caused by totally edentulous and damaged mandible by using abutments with different lengths and prosthesis filling material. At the first step of this study, prosthesis data were obtained by optical scanning method. The data were then used to design an implant model suited to prosthesis using Solidwork programs. Later, 3-D model of assembly with abutment and mandible (soft bone, hard bone and mucosa) was created. Two different damaged parts of 2.5 and 4.5 mm in depth were created with the aid of Solidwork program on the right hand side of the mandible. Implants were then applied between the foremen channels. Later, the damaged models were recovered by abutment with different lengths as ...
Journal of Engineering Materials and Technology, 2019
This study aimed to investigate the micro deep drawability of Zn-22Al alloy at room temperature i... more This study aimed to investigate the micro deep drawability of Zn-22Al alloy at room temperature in which it shows superplastic properties. To this goal, two-step equal channel angular extrusion (ECAE) process was carried out to obtain an ultra-fine grained structure (UFG), first. Upon achieving the grain size of 200 nm, the formability of the alloy at room temperature and at a high strain rate was investigated both experimentally and numerically. Micro deep drawing experiments were performed at different deep drawing ratios (1.66, 1.84, 2.0 and 2.25) and for different sheet thicknesses (0.2, 0.4 and 0.6 mm). Finite element model of the micro deep drawing was also established to assess and compare the thickness variation in deep drawn parts. Results showed that the superplastic Zn-22Al alloy has a great potential in microforming applications. It was also noted that the limiting drawing ratio can be obtained as high as 2.25 in room temperature condition.
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Papers by Hasan Sofuoğlu