Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
5 results
Search Results
Article Citation - WoS: 1Citation - Scopus: 2Oluklu alüminyum sandviç panellerde kor yüksekliğinin enerji sönümleme kapasitesine olan etkisi(Gazi Üniversitesi, 2020) Kılıçaslan, Cenk; Güden, MustafaIn this study, energy absorbing capacity of brazed and polyurethane adhesively bonded corrugated aluminum sandwich panels were investigated. In sandwich panels, Al 1050 H14 trapezoidal zig-zag corrugated cores and face and interlayer sheets were used. Each sandwich panel has core orientation of 0 degrees/0 degrees or 0 degrees/90 degrees. The cores used in these panels were smaller, core height is about 3 mm, in contrast to conventional sandwich cores. Impact tests were conducted at 3 and 6 m/s with spherical projectors. Adhesively bonded sandwich panels were also tested at 6 m/s with flat and conical projectors. Numerical models were prepared in LSDYNA to investigated the deformation behavior of cores. Panels tested with flat and conical projectors experienced complete perforation and absorbed more energy at configuration of 0 degrees/0 degrees core orientation. However, panels tested with spherical projectors were not perforated and they absorbed more energy at configuration of 0 degrees/90 degrees core orientation. Energy absorbing capacity of the panels were also compared to the panels having 9 mm height corrugated cores. The results showed that effective collapsing length was seen to increase due to increase in core height and impact energy distributed the whole panel surface more homogenous manner.Article Citation - WoS: 27Citation - Scopus: 30Single- and Double-Layer Aluminum Corrugated Core Sandwiches Under Quasi-Static and Dynamic Loadings(SAGE Publications Inc., 2016) Kılıçaslan, Cenk; Odacı, İsmet Kutlay; Güden, MustafaThe crushing of single- and double-layer zig-zag trapezoidal corrugated core sandwiches was investigated experimentally and numerically at quasi-static and dynamic rates. The buckling stress of sandwiches increased when the rate increased from quasi-static to dynamic. The increased buckling stresses were ascribed to the micro-inertial effects, which altered the buckling mode of the core from three plastic hinges to higher number of plastic hinge formations. The initial buckling stress was numerically shown to be imperfection sensitive when the imperfection size was comparable with the buckling length. The numerical buckling stresses of zig-zag and straight corrugated cores were similar, while higher inertial effects were found in triangular corrugated core.Article Citation - WoS: 11Citation - Scopus: 10Experimental Testing and Full and Homogenized Numerical Models of the Low Velocity and Dynamic Deformation of the Trapezoidal Aluminium Corrugated Core Sandwich(John Wiley and Sons Inc., 2014) Kılıçaslan, Cenk; Odacı, İsmet Kutlay; Taşdemirci, Alper; Güden, MustafaThe simulations of the low velocity and dynamic deformation of a multi-layer 1050-H14 Al trapezoidal zig-zag corrugated core sandwich were investigated using the homogenized models (solid models) of a single core layer (without face sheets). In the first part of the study, the LS-DYNA MAT-26 material model parameters of a single core layer were developed through experimental and numerical compression tests on the single core layer. In the second part, the fidelities of the developed numerical models were checked by the split-Hopkinson pressure bar direct impact, low velocity compression and indentation and projectile impact tests. The results indicated that the element size had a significant effect on the initial peak and post-peak stresses of the homogenized models of the direct impact testing of the single-layer corrugated sandwich. This was attributed to the lack of the inertial effects in the homogenized models, which resulted in reduced initial peak stresses as compared with the full model and experiment. However, the homogenized models based on the experimental stress–strain curve of the single core layer predicted the low velocity compression and indentation and projectile impact tests of the multi-layer corrugated sandwich with an acceptable accuracy and reduced the computational time of the models significantly.Article Citation - WoS: 36Citation - Scopus: 45Cross Wedge Rolling of a Ti6al4v (eli) Alloy: the Experimental Studies and the Finite Element Simulation of the Deformation and Failure(Springer Verlag, 2012) Çakırcalı, Metin; Kılıçaslan, Cenk; Güden, Mustafa; Kıranlı, Engin; Shchukin, Valery Y.; Petronko, Vladimir V.The cross wedge rolling (CWR) deformation and fracture of a Ti6Al4Al (ELI) alloy were investigated experimentally and numerically using a coupled thermomechanical finite element model analysis. The experimentally determined flow stress and damage model parameters were verified by tension split Hopkinson pressure bar testing of notched samples. The simulation and experimental CWR forces showed well agreements except near the end of the stretching zone. The model analysis showed that the temperature distribution in the work piece was nonuniform during the CWR. When the initial temperature of the work piece was relatively low, the work piece temperature increased, a heating effect of the plastic deformation, while relatively high initial work piece temperatures resulted in cooling the work piece, caused by the work piece contact with the tools. The cracks were shown numerically to initiate in the midsections of the work piece during the guiding action and elongated in a direction normal to the maximum tensile stress triaxiality, resulting in cruciformshaped crack formation, which was well agreed with the previously observed crack shape.Article Citation - WoS: 70Citation - Scopus: 81Experimental and Numerical Studies on the Quasi-Static and Dynamic Crushing Responses of Multi-Layer Trapezoidal Aluminum Corrugated Sandwiches(Elsevier Ltd., 2014) Kılıçaslan, Cenk; Güden, Mustafa; Kutlay Odacı, İsmet; Taşdemirci, AlperThe axial crushing responses of bonded and brazed multi-layer 1050 H14 trapezoid alaluminum corru- gated core (fin) sandwich structures, with and without aluminum interlayer sheets in 0°/0° and 0°/90° core orientations, were both experimentally and numerically investigated at quasi-static and dynamic strain rates. Multi-layering the core layers decreased the buckling stress and increased the densification strain. The experimental and simulation compression stress–strain curves showed reasonable agree-ments with each other. Two main crushing modes were observed experimentally and numerically: the progressive fin folding and the shearing interlayer aluminum sheets. Both, the simulation and experimental buckling and post-buckling stresses increased when the interlayer sheets were constraint laterally. The multi-layer samples without interlayer sheets in 0°/90° core orientation exhibited higher buckling stresses than the samples in 0°/0° core orientation. The increased buckling stress of 0°/0° oriented core samples without interlayer sheets at high strain rate was attributed to the micro-inertial effects which led to increased bending forces at higher impact velocities.