Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 21Citation - Scopus: 24Development and Mechanical Behavior of Fml/Aluminium Foam Sandwiches(Springer Verlag, 2013) Baştürk, Suat Bahar; Tanoğlu, Metin; Tanoğlu, Metin; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn this study, the Fiber-Metal Laminates (FMLs) containing glass fiber reinforced polypropylene (GFPP) and aluminum (Al) sheet were consolidated with Al foam cores for preparing the sandwich panels. The aim of this article is the comparison of the flexural properties of FML/Al foam sandwich panels bonded with various surface modification approaches (silane treatment and combination of silane treatment with polypropylene (PP) based film addition). The FML/foam sandwich systems were fabricated by laminating the components in a mould at 200 A degrees C under 1.5 MPa pressure. The energy absorbtion capacities and flexural mechanical properties of the prepared sandwich systems were evaluated by mechanical tests. Experiments were performed on samples of varying foam thicknesses (8, 20 and 30 mm). The bonding among the sandwich components were achieved by various surface modification techniques. The Al sheet/Al foam sandwiches were also consolidated by bonding the components with an epoxy adhesive to reveal the effect of GFPP on the flexural performance of the sandwich structures.Article Citation - WoS: 8Citation - Scopus: 8The Effect of Single-Walled Carbon Nanotube (swcnt) Concentration on the Mechanical and Rheological Behavior of Epoxy Matrix(Springer Verlag, 2020) Ay, Z.; Tanoğlu, Metin; Tanoğlu, Metin; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe improvement of Mode I fracture toughness of epoxy by the addition of single-walled carbon nanotubes (SWCNTs) is considered. To prepare nanocomposites, chemical-vapor-deposition-grown SWCNTs noncovalently functionalized with an ethoxylated alcohol was used as the additive and a diglycidyl ether of bisphenol-A-based epoxy as the matrix material. The SWCNTs were dispersed in the epoxy matrix via a mechanical stirrer and a 3-roll mill. The effect of their concentration (0.0125, 0.025, 0.05, 0.1, 0.3, and 0.5 wt.%) on the mechanical properties of the nanocomposites was investigated, and the optimum concentration was determined. Mode I fracture toughness (single-edge-notch 3-point bending) and tensile tests were carried out on neat epoxy and SWCNT-reinforced epoxy nanocomposites. The fractured surfaces of fracture toughness and tensile test specimens were examined by the SEM to reveal the effect of SWCNTs on their failure modes.Conference Object Citation - WoS: 2Citation - Scopus: 2Function Generation Synthesis of Planar Slider-Crank Linkages for Given 3 Positions and a Dead-Center Position(Springer Verlag, 2020) Kiper, Gokhan; Gorgulu, Ibrahimcan; Görgülü, İbrahimcan; Kiper, Gökhan; Küçükoğlu, Sefa Furkan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyFunction generation for finitely many positions and dead-center design problems are generally separately handled in the literature. This paper presents a mixed formulation for planar slider-crank linkages where three precision points and a folded or extended dead-center position are to be satisfied. The formulation results in an 8th degree univariate. Examples show that generally there are four real solutions, only two of which result in distinct solutions.Article Citation - WoS: 47Citation - Scopus: 46Surface Charge-Dependent Transport of Water in Graphene Nano-Channels(Springer Verlag, 2018) Çelebi, Alper Tunga; Barışık, Murat; Beşkök, Ali; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyDeionized water flow through positively charged graphene nano-channels is investigated using molecular dynamics simulations as a function of the surface charge density. Due to the net electric charge, Ewald summation algorithm cannot be used for modeling long-range Coulomb interactions. Instead, the cutoff distance used for Coulomb forces is systematically increased until the density distribution and orientation of water atoms converged to a unified profile. Liquid density near the walls increases with increased surface charge density, and the water molecules reorient their dipoles with oxygen atoms facing the positively charged surfaces. This effect weakens away from the charged surfaces. Force-driven water flows in graphene nano-channels exhibit slip lengths over 60 nm, which result in plug-like velocity profiles in sufficiently small nano-channels. With increased surface charge density, the slip length decreases and the apparent viscosity of water increases, leading to parabolic velocity profiles and decreased flow rates. Results of this study are relevant for water desalination applications, where optimization of the surface charge for ion removal with maximum flow rate is desired.Article Citation - WoS: 35Citation - Scopus: 39Development of Graphene Nanoplatelet-Reinforced Az91 Magnesium Alloy by Solidification Processing(Springer Verlag, 2018) Kandemir, Sinan; Kandemir, Sinan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIt is a challenging task to effectively incorporate graphene nanoplatelets (GNPs) which have recently emerged as potential reinforcement for strengthening metals into magnesium-based matrices by conventional solidification processes due to their large surface areas and poor wettability. A solidification processing which combines mechanical stirring and ultrasonic dispersion of reinforcements in liquid matrix was employed to develop AZ91 magnesium alloy matrix composites reinforced with 0.25 and 0.5 wt.% GNPs. The microstructural studies conducted with scanning and transmission electron microscopes revealed that fairly uniform distribution and dispersion of GNPs through the matrix were achieved due to effective combination of mechanical and ultrasonic stirring. The GNPs embedded into the magnesium matrix led to significant enhancement in the hardness, tensile strength and ductility of the composites compared to those of unreinforced AZ91 alloy. The strength enhancement was predominantly attributed to the grain refinement by the GNP addition and dislocation generation strengthening due to the coefficient of thermal expansion mismatch between the matrix and reinforcement. The improved ductility was attributed to the refinement of β eutectics by transforming from lamellar to the divorced eutectics due to the GNP additions. In addition, the strengthening efficiency of the composite with 0.25 wt.% GNP was found to be higher than those of the composite with 0.5 wt.% GNP as the agglomeration tendency of GNPs is increased with increasing GNP content. These results were compared with those of the GNP-reinforced magnesium composites reported in the literature, indicating the potential of the process introduced in this study in terms of fabricating light and high-performance metal matrix composites.Conference Object Citation - Scopus: 2Function Generation Synthesis With Planar 4-Bar Linkage as a Mixed Problem of Correlation of Crank Angles and Dead-Center Design(Springer Verlag, 2019) Kiper, Gökhan; Kiper, Gökhan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe function generation synthesis of planar four-bar linkage is formulated as a mixed problem of correlation or crank angles and dead-center design. The syn-thesis is based on three desired configurations of the linkage, where the input and output joint angles are specified for two of the configurations and the coupler link is folded upon the output link for the third configuration. The formulation results in a set of nonlinear equations which can be solved analytically. The formulations are tested with numerical examples and similar mixed function generation problems are briefly discussed.Conference Object Citation - Scopus: 1Structural Compliance Effects on the Accuracy and Safety of a R-Cube Haptic Device(Springer Verlag, 2019) Carbone, Giuseppe; Acinapura, Antonio; Görgülü, İbrahimcan; Dede, Mehmet İsmet Can; Dede, Mehmet İsmet Can; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis paper addresses the contribution of structural compliance on stiffness and safety of a R-CUBE Haptic Device. Structural compliance is determined in several poses via FEM analysis and addressed by referring to local and global indices of performance. Results are also compared with evidences from experimental tests. Comparison of numerical and experimental data allows to identify and separate the contributions to the overall compliance that are due to the structural stiffness, and other contributions such as joint clearance, pose and loading conditions.Book Part Control Methods for a Teleoperated Endoscope Robot(Springer Verlag, 2019) Işıtman, Oğulcan; Dede, Mehmet İsmet Can; Işıtman, Oğulcan; Dede, Mehmet İsmet Can; 01. Izmir Institute of Technology; 03.10. Department of Mechanical Engineering; 03. Faculty of EngineeringIn this study, control of a endoscope robot for the pituitary gland surgery is presented. This co-worker robot has non-backdrivable actuation system with external brakes on the actuators. Since it is required to move in a constrained environment, which is the inside the nostrils in this case, modifications are required for the motion controller. In order to provide safe procedure, the maximum force and torque limits are defined for the real surgical case by using human cadaver head. By considering these limits and application specific requirements, a compliance controller is proposed and experimentally tested.Conference Object Kinematic Synthesis of Planar 4-Bar Path Generators for Finite Line Positions(Springer Verlag, 2019) Kiper, Gökhan; Kiper, Gökhan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAlthough the kinematic synthesis of planar function, point-path and motion gen-erators are vastly studied in the literature, surprisingly synthesis of line-path gen-erators is not formulized in detail. This study presents the formulization of the planar 4-bar line-path generator synthesis problem for up to 5 homologous posi-tions. Numerical examples for 3 and 4 line positions are presented for the illustra-tion of the formulations.Conference Object Citation - Scopus: 4Static Force Balancing of a 2r1t Parallel Manipulator With Remote Center of Motion(Springer Verlag, 2019) Yaşır, Abdullah; Kiper, Gökhan; Dede, Mehmet İsmet Can; Kiper, Gökhan; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAssistive robots in surgical applications should be gravity balanced due to safety considerations. This study presents a gravity balancing solution for a 3-degree-of-freedom parallel manipulator to be used as an endoscope navigation robot for transnasal minimal invasive surgery applications. The manipulator has a rather simple structure that allows individual balancing of the three legs in their respec-tive planes of motion. First, sole counter-mass balancing is investigated, but it is seen that the extra mass amount is too much. Sole spring balancing is not consid-ered as an option due to constructional complexity. A hybrid solution as a combi-nation of counter-mass and spring balancing is devised. In the proposed solution, the masses on the distal links of a leg are balanced with counter-masses so that all masses are lumped to the link connected to the base of the manipulator. Hence the problem is simplified into the balancing of a pendulum. The necessary formula-tions are derived and numerical calculations demonstrate that the hybrid balancing yields a feasible solution.