Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

Browse

Filters

2010 - 201922020 - 20231

Settings

Department: search.filters.department.İzmir Institute of Technology. Mechanical EngineeringSubject: search.filters.subject.Anisotropy

Search Results

Now showing 1 - 3 of 3
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Quasi-Static and Dynamic Brazilian Testing and Failure Analysis of a Deer Antler in the Transverse To the Osteon Growth Direction
    (Elsevier, 2023) Orhan, Mehmet; Sarıkaya, Mustafa Kemal; Taşdemirci, Alper; Tuncer, Can; Güden, Mustafa
    The transverse tensile strength of a naturally fallen red deer antler (Cervus Elaphus) was determined through indirect Brazilian tests using dry disc-shape specimens at quasi-static and high strain rates. Dynamic Brazilian tests were performed in a compression Split-Hopkinson Pressure Bar. Quasi-static tensile and indirect Brazilian tests were also performed along the osteon growth direction for comparison. The quasi-static transverse tensile strength ranged 31.5–44.5 MPa. The strength increased to 83 MPa on the average in the dynamic Brazilian tests, proving a rate sensitive transverse strength. The quasi-static tensile strength in the osteon growth direction was however found comparably higher, 192 MPa. A Weibull analysis indicated a higher tensile ductility in the osteon growth direction than in the transverse to the osteon growth direction. The microscopic analysis of the quasi-static Brazilian test specimens (tensile strain along the osteon growth direction) revealed a micro-cracking mechanism operating by the crack deflection/twisting at the lacunae in the concentric lamellae region and at the interface between concentric lamellae and interstitial lamellae. On the other side, the specimens in the transverse direction fractured in a more brittle manner by the separation/delamination of the concentric lamellae and pulling of the interstitial lamellae. The detected increase in the transverse strength in the high strain rate tests was further ascribed to the pull and fracture of the visco-plastic collagen fibers in the interstitial lamellae. This was also confirmed microscopically; the dynamically tested specimens exhibited flatter fracture surfaces. © 2023 Elsevier Ltd
  • Article
    Citation - WoS: 15
    Citation - Scopus: 14
    Development of Electrically Conductive and Anisotropic Gel-Coat Systems Using Cnts
    (Elsevier Ltd., 2013) İnce Yardımcı, Atike; Tanoğlu, Metin; Selamet, Yusuf
    Electrical conductivity of an unsaturated thermoset polyester based gel-coat system containing 0.05 wt.% of carbon nanotubes (CNTs) was investigated. The CNTs used were synthesized by chemical vapor deposition method by methane decomposition and Raman characterization showed that they were mostly single walled and high quality. To disperse CNTs in the gel-coat resin, 3-roll milling technique was used. It was found that as the CNTs are added to gel-coat system, resistivity value decreases significantly while neat gel-coat showed a high resistivity. By the application of an AC electrical field during curing process, it was attempted to align CNTs in the gel-coat resin and an electrically anisotropic polymer was obtained. © 2012 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 23
    Citation - Scopus: 27
    Electric Field Effects on Cnts/Vinyl Ester Suspensions and the Resulting Electrical and Thermal Composite Properties
    (Elsevier Ltd., 2010) Yurdakul, Hilmi; Seyhan, Abdullah Tuğrul; Turan, Servet; Tanoğlu, Metin; Bauhofer, Wolfgang; Schulte, Karl
    In this study, electrical conductivity of a vinyl ester based composite containing low content (0.05, 0.1 and 0.3wt.%) of double and multi-walled carbon nanotubes with and without amine functional groups (DWCNTs, MWCNTs, DWCNT-NH2 and MWCNT-NH2) was investigated. The composite with pristine MWCNTs was found to exhibit the highest electrical conductivity. Experiments aimed to induce an aligned conductive network with application of an alternating current (AC) electric field during cure were carried out on the resin suspensions with MWCNTs. Formation of electric anisotropy within the composite was verified. Light microscopy (LM), scanning electron (SEM) and transmission electron microscopy (TEM) were conducted to visualize dispersion state and the extent of alignment of MWCNTs within the polymer cured with and without application of the electric field. To gain a better understanding of electric field induced effects, glass transition temperature (Tg) of the composites was measured via Differential Scanning Calorimetry (DSC). It was determined that at 0.05wt.% loading rate of MWCNTs, the composites, cured with application of the AC electric field, possessed a higher Tg than the composites cured without application of the AC electric field. © 2010 Elsevier Ltd.