Mehmet Şenel - Academia.edu (original) (raw)
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Papers by Mehmet Şenel
Co-continuous alumina–aluminium composite materials with excellent physical and mechanical prope... more Co-continuous alumina–aluminium composite materials with
excellent physical and mechanical properties offer great potentials for lightweight, wear-resistant and high-temperature applications. They combine metallic properties of matrix alloys (ductility and toughness) with ceramic properties of reinforcements (high strength and high modulus), leading to greater strength in shear and compression and higher service temperature capabilities. Composite materials prepared from a liquid-phase displacement reaction present a
unique microstructure in which each phase is a continuous network penetrated by the network of the other constituent. In this study, aluminium–alumina matrix composites reinforced with glass bubbles with low thermal and electrical conductivities are presented. Different characterisation techniques were used to determine physical–mechanical properties. Porosity and density measurements were carried out by means of helium gas pycnometer and basic materials parameters were compared such as effect of the sintering process,
thermal conductivity and percentage of the wax. Drop weigh tests, semi-static compression tests and also scratch tests were applied to measure the general mechanical and damage behaviour of these composites. Microstructural and fracture behaviour were evaluated by scanning electron microscopy.
Bu çalışmada, imalatı yapılmış olan düşük hızlı darbe test düzeneğine monte edilecek şekilde özgü... more Bu çalışmada, imalatı yapılmış olan düşük hızlı darbe test düzeneğine monte edilecek şekilde özgün bir frenleme ve kontrol sistemi tasarlanmış ve imalatı gerçekleştirilmiştir. Frenleme sisteminin numune hasar oluşumu üzerine farkını görmek için düşük hızlı darbe deneyleri yapılmıştır. Deneylerde numune olarak 8 tabakalı simetrik [-30/30] 4s oryantasyon açısında epoxy-cam elyaf kompozit plak kullanılmıştır. Deneyler 14.7J, 22.07J, 29.43J ve 44,14J darbe enerjilerinde yapılmıştır. Sonuç olarak düzenekte kullanılan frenleme ve kontrol sistemi, düşen kütlenin sekmesi durumunda kütleyi tutmuş, numuneyi delme durumunda da devreye girmeyerek istenilen özellikleri göstermiştir. Frenleme sisteminin hasar oluşumuna etkisi incelenerek bu sisteminin gerekliliği ve gerçek modellemeye yakınlığı tespit edilmiştir. Anahtar kelimeler: Frenleme ve kontrol sitemi, düşük hızlı darbe, kompozit malzeme.
An experimental and numerical study on the influence of biaxial preloading on the low velocity im... more An experimental and numerical study on the influence of biaxial preloading on the low velocity impact performance of E-glass/epoxy-laminated composite plates was conducted. For this aim, an experimental device was developed to apply the load in two perpendicular directions. Three preload cases, representative of actual structures were selected, biaxially tension, compression and, tension-compression (shear) loading cases. The samples were produced from unidirectional reinforced E-glass and epoxy, by using a hand lay-up technique. Laminated E-glass/epoxy with stacking sequence [0/90] 2s , dimensions were 140 × 140 mm 2 and a thickness of 2 mm for the samples used. Finite element analysis (FEA) was developed, using Hashin failure criteria for the composite material, and material models implemented by a User Material Subroutine into ABAQUS ® /explicit software, in order to simulate the failure mechanisms and force–time histories. Force–time and energy–time data were obtained by means of user material subroutine from the finite element model. The finite element results showed a good correlation to the experimental data in terms of force–time, energy–time graph or failure in composite plate, although these numerical results strongly depended on simulation parameters like mesh size or the number of element.
Co-continuous alumina–aluminium composite materials with excellent physical and mechanical prope... more Co-continuous alumina–aluminium composite materials with
excellent physical and mechanical properties offer great potentials for lightweight, wear-resistant and high-temperature applications. They combine metallic properties of matrix alloys (ductility and toughness) with ceramic properties of reinforcements (high strength and high modulus), leading to greater strength in shear and compression and higher service temperature capabilities. Composite materials prepared from a liquid-phase displacement reaction present a
unique microstructure in which each phase is a continuous network penetrated by the network of the other constituent. In this study, aluminium–alumina matrix composites reinforced with glass bubbles with low thermal and electrical conductivities are presented. Different characterisation techniques were used to determine physical–mechanical properties. Porosity and density measurements were carried out by means of helium gas pycnometer and basic materials parameters were compared such as effect of the sintering process,
thermal conductivity and percentage of the wax. Drop weigh tests, semi-static compression tests and also scratch tests were applied to measure the general mechanical and damage behaviour of these composites. Microstructural and fracture behaviour were evaluated by scanning electron microscopy.
Bu çalışmada, imalatı yapılmış olan düşük hızlı darbe test düzeneğine monte edilecek şekilde özgü... more Bu çalışmada, imalatı yapılmış olan düşük hızlı darbe test düzeneğine monte edilecek şekilde özgün bir frenleme ve kontrol sistemi tasarlanmış ve imalatı gerçekleştirilmiştir. Frenleme sisteminin numune hasar oluşumu üzerine farkını görmek için düşük hızlı darbe deneyleri yapılmıştır. Deneylerde numune olarak 8 tabakalı simetrik [-30/30] 4s oryantasyon açısında epoxy-cam elyaf kompozit plak kullanılmıştır. Deneyler 14.7J, 22.07J, 29.43J ve 44,14J darbe enerjilerinde yapılmıştır. Sonuç olarak düzenekte kullanılan frenleme ve kontrol sistemi, düşen kütlenin sekmesi durumunda kütleyi tutmuş, numuneyi delme durumunda da devreye girmeyerek istenilen özellikleri göstermiştir. Frenleme sisteminin hasar oluşumuna etkisi incelenerek bu sisteminin gerekliliği ve gerçek modellemeye yakınlığı tespit edilmiştir. Anahtar kelimeler: Frenleme ve kontrol sitemi, düşük hızlı darbe, kompozit malzeme.
An experimental and numerical study on the influence of biaxial preloading on the low velocity im... more An experimental and numerical study on the influence of biaxial preloading on the low velocity impact performance of E-glass/epoxy-laminated composite plates was conducted. For this aim, an experimental device was developed to apply the load in two perpendicular directions. Three preload cases, representative of actual structures were selected, biaxially tension, compression and, tension-compression (shear) loading cases. The samples were produced from unidirectional reinforced E-glass and epoxy, by using a hand lay-up technique. Laminated E-glass/epoxy with stacking sequence [0/90] 2s , dimensions were 140 × 140 mm 2 and a thickness of 2 mm for the samples used. Finite element analysis (FEA) was developed, using Hashin failure criteria for the composite material, and material models implemented by a User Material Subroutine into ABAQUS ® /explicit software, in order to simulate the failure mechanisms and force–time histories. Force–time and energy–time data were obtained by means of user material subroutine from the finite element model. The finite element results showed a good correlation to the experimental data in terms of force–time, energy–time graph or failure in composite plate, although these numerical results strongly depended on simulation parameters like mesh size or the number of element.