WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Author: search.filters.author.Toksoy, Ahmet KaanInstitution Author: search.filters.institutionAuthor.Güden, Mustafa

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Now showing 1 - 10 of 10
  • Article
    Citation - WoS: 71
    Citation - Scopus: 78
    The Strengthening Effect of Polystyrene Foam Filling in Aluminum Thin-Walled Cylindrical Tubes
    (Elsevier Ltd., 2005) Toksoy, Ahmet Kaan; Güden, Mustafa
    The strengthening effect of foam filling in thin-walled circular tubes, deforming in diamond and concertina modes, was investigated in polystyrene foam filled aluminum tubes. Empty tubes of two different diameters (16 and 25 mm) deformed in diamond mode, while foam filling changed the deformation mode into concertina in 25 mm tube due to thickening effect of foam filling. The strengthening coefficient in concertina mode was found around unity, while in diamond mode it was greater than unity. In concertina mode, foam and tube were observed to deform independently. However, in diamond mode, foam was compressed in between the folds, leading to a higher strengthening coefficient. The effects of deformation rate and the use adhesive on the average crushing loads of the filled tubes were also determined.
  • Article
    Citation - WoS: 29
    Citation - Scopus: 32
    The Optimisation of the Energy Absorption of Partially Al Foam-Filled Commercial 1050h14 and 6061t4 Al Crash Boxes
    (Taylor and Francis Ltd., 2011) Toksoy, Ahmet Kaan; Güden, Mustafa
    Partially Alulight and Hydro Al closed-cell foam-filled commercial 1050H14 Al and 6061T4 Al crash boxes were optimised using the response surface methodology in order to maximise specific energy absorption (SEA). The quasi-static crushing of empty and filled crash boxes was simulated using LS-DYNA, and the results were further confirmed with experimental quasi-static crushing testing of empty and Alulight foam-filled commercial 1050H14 Al crash boxes. Results showed that partial foam filling of commercial crash boxes increased both SEA and mean load because of foam filler axial and lateral deformation in between the progressing folds of the crash box. Within the studied constraint range of box mean load, box wall thickness and foam filler density, the optimised Alulight and Hydro foam-filled 1050H14 and 6061T4 crash boxes resulted in 26%–40% increase in total energy absorption as compared with empty crash boxes. Considering the same weight basis, the use of a higher yield strength box wall material and higher plateau stresses of Al foam filler resulted in higher energy absorptions in partial foam-filled boxes at relatively low displacements.
  • Article
    Citation - WoS: 54
    Citation - Scopus: 62
    Sic-Particulate Aluminum Composite Foams Produced by Powder Compacts: Foaming and Compression Behavior
    (Springer Verlag, 2003) Elbir, Semih; Yılmaz, Selahattin; Toksoy, Ahmet Kaan; Güden, Mustafa; Hall, Ian W.
    The foaming behavior of SiC-particulate (8.6% by volume) aluminum composite powder compacts contained Titanium Hydride blowing agent was investigated by heating above the melting temperature (750°C) in a pre-heated furnace. Aluminum powder compacts were also prepared and foamed using similar compaction and foaming parameters in order to determine the effect of SiC-particulate addition on foaming and compression behavior. The linear expansions of the compacts at various furnace holding times were ex situ determined. Optical and scanning electron microscopy techniques were used to characterize prepared and deformed foams microstructures. The SiC-particulate addition was found to increase the linear expansion and reduce the extent of the liquid metal drainage and cell coarsening of the aluminum compacts. The composite foam samples also showed higher compressive stresses, but a more brittle behavior as compared with aluminum foams.
  • Article
    Citation - WoS: 123
    Citation - Scopus: 139
    Quasi-Static Axial Crushing of Extruded Polystyrene Foam-Filled Thin-Walled Aluminum Tubes: Experimental and Numerical Analysis
    (Elsevier Ltd., 2006) Aktay, Levent; Toksoy, Ahmet Kaan; Güden, Mustafa
    The experimental and numerical quasi-static crushing responses of extruded closed cell polystyrene foam-filled thin-walled aluminum tubes were investigated. The numerical crash analysis of empty and foam-filled tubes was performed using the explicit finite element code PAM-CRASH™. Satisfactory agreements were generally achieved between the finite element model and experimental deformed shapes, load–displacements, fold lengths and specific energy absorptions. The model and experiments have also highlighted the several effects of foam filling on the crushing of thin-walled tubes. The energy absorptions in foam-filled tubes were further shown to be higher than the sum of the energy absorptions of empty tube (alone) and filler (alone).
  • Article
    Citation - WoS: 153
    Citation - Scopus: 163
    Predicting Energy Absorption in a Foam-Filled Thin-Walled Aluminum Tube Based on Experimentally Determined Strengthening Coefficient
    (Elsevier Ltd., 2006) Kavi, Halit; Toksoy, Ahmet Kaan; Güden, Mustafa
    The energy absorption in a foam-filled thin-walled circular Al tube was investigated based on the experimentally determined strengthening coefficient of filling using Al and polystyrene closed-cell foams with three different densities. Foam filling was found to change the deformation mode of tube from diamond (empty tube) into concertina, regardless the foam type and density used. Although foam filling resulted in higher energy absorption than the sum of the energy absorptions of the tube alone and foam alone, it was not effective in increasing the specific energy than simply thickening the tube wall. It was shown that for efficient foam filling an appropriate foam-tube combination must be selected by taking into account the magnitude of strengthening coefficient of foam filling and the foam filler plateau load.
  • Article
    Citation - WoS: 40
    Citation - Scopus: 52
    Partial Al Foam Filling of Commercial 1050h14 Al Crash Boxes: the Effect of Box Column Thickness and Foam Relative Density on Energy Absorption
    (Elsevier Ltd., 2010) Toksoy, Ahmet Kaan; Güden, Mustafa
    The crushing behavior of partially Al closed-cell foam filled commercial 1050H14 Al crash boxes was determined at quasi-static and dynamic deformation velocities. The quasi-static and dynamic crushing of the boxes were simulated using the LS-DYNA. The results showed that partial foam filling tended to change the deformation mode of empty boxes from a non-sequential to a sequential folding mode. In general, the experimental and simulation results showed similar mean load values and deformation modes. The SEA values of empty, partially and fully foam filled boxes were predicted as function of box wall thickness between 1 and 3 mm and foam filler relative density between 0 and 0.2, using the analytical equations developed for the mean crushing loads. The analysis indicated that both fully and partially foam filled boxes were energetically more efficient than empty boxes above a critical foam filler relative density. Partial foam filling, however, decreases the critical foam filler density at increasing box wall thicknesses.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 14
    Modeling the Progressive Axial Crushing of Foam-Filled Aluminum Tubes Using Smooth Particle Hydrodynamics and Coupled Finite Element Model/Smooth Particle Hydrodynamics
    (Elsevier Ltd., 2008) Aktay, Levent; Johnson, Alastair F.; Toksoy, Ahmet Kaan; Kröplin, Bernd Helmut; Güden, Mustafa
    As alternatives to the classical finite element model (FEM), a meshless smooth particle hydrodynamics (SPH) method, in which the discrete particles represent a solid domain, and a coupled FEM/SPH modeling technique were investigated for the numerical simulation of the quasi-static axial crushing of polystyrene foam-filled aluminum thin-walled aluminum tubes. The results of numerical simulations, load-deformation histories, fold lengths and specific absorbed energies, were found to show satisfactory correlations with those of experiments and FEM. The results further proved the capabilities of the SPH Method and coupled FEM/SPH modeling technique in predicting the crushing behavior of foam-filled thin-walled tubes.
  • Article
    Citation - WoS: 53
    Citation - Scopus: 56
    Finite Element and Coupled Finite Element/Smooth Particle Hydrodynamics Modeling of the Quasi-Static Crushing of Empty and Foam-Filled Single, Bitubular and Constraint Hexagonal- and Square-Packed Aluminum Tubes
    (Elsevier Ltd., 2008) Aktay, Levent; Kröplin, Bernd Helmut; Toksoy, Ahmet Kaan; Güden, Mustafa
    The quasi-static axial crushing behavior of empty and Al and polystyrene foam-filled Al single, bitubular and multi-tube-packed (hexagonal and square packing) configurations were investigated experimentally and numerically. Tubes were modeled using finite element and coupled finite element/smooth particle hydrodynamics. The numerical specific absorbed energy (SAE) values, deformation patterns, load values and number of folds formed were found to show agreements with those of experiments. Among the tested tube configurations only hexagonal- and square-packed empty tube designs showed increased SAE values over that of single empty tube. Furthermore, foam-filled multi-tube designs both hexagonal- and square-packed designs were found energetically more efficient than Al foam-filled single tubes at similar foam filler densities. The increased SAE values of multi-tubes were attributed to the frictional forces of the multi-tube designs and constraining effect of the die walls accommodating the tubes.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 19
    Experimental Investigation of Interaction Effects in Foam-Filled Thin-Walled Aluminum Tubes
    (Springer Verlag, 2006) Güden, Mustafa; Toksoy, Ahmet Kaan; Kavi, Halit
    The interaction coefficients of polystyrene foam filling of thin-walled aluminum cylindrical tubes were investigated experimentally through compression testing of partially foam-filled tubes with and without adhesive. The experimental load-displacement curves and observation of the crushed sections of filled tubes have shown that partial foam filling reduced the fold length and hence increased the average crushing loads of tubes, proving the interaction effect between tube wall and filler. The interaction coefficients for the partial foam filling were further calculated to be in the level and/or higher than that of the foam plateau load of transverse direction.
  • Article
    Citation - WoS: 29
    Citation - Scopus: 29
    Effect of Adhesive on the Strengthening of Aluminum Foam-Filled Circular Tubes
    (Springer Verlag, 2004) Toksoy, Ahmet Kaan; Tanoğlu, Metin; Güden, Mustafa; Hall, Ian W.
    Studies of the crushing behavior of closed-cell, aluminum foam-filled aluminum and steel tubes have shown an interaction effect between tubewall and foam filler [1, 2, 3]. The crushing loads of foam-filled tubes are, therefore, found to be higher than the sum of the crushing loads of foam (alone) and tube (alone) mainly due to this effect. Santosa et al. [1], based on FEM results, proposed the following equation for the average crushing load of foam-filled square tubes of length b,