Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article The Effect of Layered Cover Plate Material on the Ballistic Performance of Ceramic Armors: Experimental and Numerical Study(Pergamon-Elsevier Science Ltd, 2026) Cellek, Seven Burcin; Tasdemirci, Alper; Cimen, Gulden; Yildiztekin, Faki Murat; Toksoy, Ahmet Kaan; Guden, MustafaThis study investigates the ballistic performance of silicon carbide (SiC) ceramic armor systems reinforced with single and hybrid metallic cover plates composed of Ti-6Al-4V (Ti64) and copper. Controlled ballistic experiments combined with validated LS-DYNA simulations were conducted to examine how cover-plate material, thickness, and stacking sequence influence penetration resistance, energy dissipation, and failure mechanisms. The experimental results revealed that metallic cover plates significantly enhance protection by improving projectile erosion and extending dwell time. While both Ti64 and copper single layers increased the antipenetration capability (APC) compared with bare SiC, hybrid configurations achieved the highest performance. The optimal design, consisting of a 2 mm Ti64 plate placed in front of a 1 mm copper plate, produced the greatest reduction in penetration depth and the highest APC value. Numerical analyses closely replicated the experimental trends and provided insight into stress-wave interactions, pressure evolution, and damage progression within the ceramic. The findings demonstrate that hybrid Ti64-Cu systems not only improve initial impact resistance but also redistribute energy toward the front layers, reducing stress transmission to the backing and mitigating catastrophic ceramic failure. The combined experimental and numerical results establish a clear design framework for developing lightweight, high-efficiency ceramic armor through tailored hybrid layering strategies.Article Novel Strut-Based Mechanical Analysis: Flow Stress Determination of Electron Beam Melt (EBM) Lattice Structures(Springernature, 2025) Bin Riaz, Muhammad Arslan; Erten, Hacer Irem; Guden, MustafaIn modeling lattices, the material flow stress equation, such as the Johnson and Cook (JC) equation, is usually determined from the mechanical tests conducted on bulk, relatively large test size specimens which were manufactured using the same process parameters with the lattices. However, the flow stresses of struts were shown in several studies to be significantly lower than those of large size test specimens. To overcome this discrepancy, a novel approach that combined the strut compression test, the strut double shear test (DST) and the numerical model of the strut DST using the JC equation was proposed. The study confirmed that the flow stress determined from the machined bulk tension test specimens overestimated the experimental compression stress-strain behavior of a body centered cubic (BCC) Ti6Al4V lattice. The flow stress parameters determined from the compression stress-strain curves of the as-printed strut specimens, on the other side, showed the best match to the experimental compression stress-strain behavior of the BCC lattice. The fidelity of the determined parameters of the JC equation was further verified with the experimental and numerical DSTs. It was also shown that the numerical iterations of DST model could be used for the fine-tuning the flow stress parameters.Article A Comparative Study on Experimental and FEA-Based Simulation of Dry Sliding Wear Behavior of Boronized AISI 304 Stainless Steel at Elevated Temperatures(Pleiades Publishing Ltd, 2025) Gok, Mustafa Sabri; Kucuk, Yilmaz; Khosravi, Farshid; Gunen, Ali; Karakas, Mustafa Serdar; Guden, MustafaIn this study, the influence of boronizing on the high-temperature wear behavior of AISI 304 was examined experimentally and with FEA simulation. Boronizing, conducted at 950 degrees C for 3 h using the powder-pack boronizing technique, showed an approximately 7-fold increase in hardness compared to untreated sample. Boride layer characterization was performed using XRD, SEM, and EDS line analyses. Wear tests were performed at ambient temperatures of 25, 250, and 500 degrees C. While the wear rates of the untreated sample increased dramatically with increasing temperature, those of the boronized samples were significantly limited. FEA simulation using the Johnson-Cook fracture model demonstrated a high degree of consistency with the experimental wear profiles and this alignment enables reliable wear predictions. The oxide layer formation was observed on the worn surface of boronized samples during the tests at elevated temperatures, resulting in less plastic deformation.Article Citation - WoS: 2Citation - Scopus: 2A Comprehensive Study on the Effectiveness of the Stress and Damage Model Parameters in Predicting the Compression Fracture Behavior of Selective Laser Melted AlSi10Mg BCC Lattices(Elsevier B.V., 2025) Guden, Mustafa; Erten, Hacer Irem; Gorguluarslan, Recep M.; Gulletutan, Umut Can; Dagkolu, Akin; Gokdag, Istemihan; Namazov, SubhanThe Johnson and Cook (JC) stress and damage model parameters determined from the machined bulk cylindrical specimens and as-built struts through tension and compression tests were used to model quasi-static compression behavior of selective laser melt-fabricated AlSi10Mg alloy lattices. The lattices had the same cell size (10 mm) and strut diameter (1 mm), but different number of cells (2 x 2 x 2, 10 x 10 x 2 and 5 x 5 x 5) and geometries (sandwich and cubic). Four different sets of JC damage model parameters (brittle and ductile notch-insensitive and compression and tension notch-sensitive) were further implemented in the lattice compression numerical models. The brittle damage model parameters and smaller mesh sizes resulted in cracking the face-sheet corner strut nodes before the occurrence of a bending-dominated initial peak stress. The notch-sensitive damage model parameters exhibited no bent-strut fracture in the middle layers of the lattices and increased the crack initiation strains as compared with the notch-insensitive damage model parameters. Despite significant variations in the initial peak stresses of the tested 2 x 2 x 2 and 10 x 10 x 2 lattices, the implication of the strut micro-tension stress model together with the compression notch-sensitive damage model parameters using 0.25 mm mesh size conservatively approximated the experimental deformation stresses while the machined bulk specimen tensionstress model over predicted the experimental stresses. On the other side, the strut stress model with 0.15 mm mesh size accurately predicted the experimental diagonal shear/fracture mode of struts with a slightly higher numerical initial peak stress. The compression tests on the strut specimens extracted from the as-built lattices yielded similar stress model parameters with the micro-tension tests. The differences between the initial peak stresses of the investigated sandwich and cubic lattices were further explained by the differences in the lattice boundary conditions.Article Citation - WoS: 8Citation - Scopus: 8A Review of the Experimental and Numerical Studies on the Compression Behavior of the Additively Produced Metallic Lattice Structures at High and Low Strain Rates(KeAi Communications Co., 2025) Bin Riaz, Muhammad Arslan; Guden, MustafaRecent advances in additive manufacturing have enabled the construction of metallic lattice structures with tailored mechanical and functional properties. One potential application of metallic lattice structures is in the impact load mitigation where an external kinetic energy is absorbed by the deformation/ crushing of lattice cells. This has motivated a growing number of experimental and numerical studies, recently, on the crushing behavior of additively produced lattice structures. The present study overviews the dynamic and quasi-static crushing behavior of additively produced Ti64, 316L, and AlSiMg alloy lattice structures. The first part of the study summarizes the main features of two most commonly used additive processing techniques for lattice structures, namely selective-laser-melt (SLM) and electrobeam-melt (EBM), along with a description of commonly observed process induced defects. In the second part, the deformation and strain rate sensitivities of the selected alloy lattices are outlined together with the most widely used dynamic test methods, followed by a part on the observed microstructures of the SLM and EBM-processed Ti64, 316L and AlSiMg alloys. Finally, the experimental and numerical studies on the quasi-static and dynamic compression behavior of the additively processed Ti6 4, 316L, and AlSiMg alloy lattices are reviewed. The results of the experimental and numerical studies of the dynamic properties of various types of lattices, including graded, non-uniform strut size, hollow, non-uniform cell size, and bio-inspired, were tabulated together with the used dynamic testing methods. The dynamic tests have been noted to be mostly conducted in compression Split Hopkinson Pressure Bar (SHPB) or Taylor-and direct-impact tests using the SHPB set-up, in all of which relatively small-size test specimens were tested. The test specimen size effect on the compression behavior of the lattices was further emphasized. It has also been shown that the lattices of Ti6 4 and AlSiMg alloys are relatively brittle as compared with the lattices of 316L alloy. Finally, the challenges associated with modelling lattice structures were explained and the micro tension tests and multi-scale modeling techniques combining microstructural characteristics with macroscopic lattice dynamics were recommended to improve the accuracy of the numerical simulations of the dynamic compression deformations of metallic lattice structures. (c) 2025 China Ordnance Society. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).Article Citation - WoS: 1Citation - Scopus: 1Dynamic Compression of Metal Syntactic Foam-Filled Aluminum Tubes(Springer, 2024) Movahedi, Nima; Güden, Mustafa; Fiedler, Thomas; Taşdemirci, Alper; Sarikaya, Mustafa; Tasdemirci, Alper; Murch, Graeme E.; Belova, Irina V.; Guden, MustafaThe current research investigates the compressive properties of metal syntactic foam (MSF)-filled tubes at dynamic loads with an impact velocity of 4 m/s. For this purpose, A356 aluminum alloy syntactic foams were prepared using an infiltration casting technique with an incorporation of expanded perlite (EP) filler particles. The study involves the testing and comparison of both MSF samples and MSF-filled tubes under dynamic loading scenarios. In the case of MSF-filled tubes, aluminum tubes are either fully filled (FFT) or half-filled (HFT) with MSFs. The manufactured foams and foam cores have a similar macroscopic density across all tested samples. Under dynamic loading, the MSF, HFT, and FFT samples exhibit distinct and different deformation mechanisms. In MSFs, dynamic compression is controlled by shearing of the sample, whereas in HFTs and FFTs, dynamic deformation occurs through the folding and buckling of the tubes, accompanied by partial deformation of the MSF cores.Article Citation - WoS: 2Citation - Scopus: 2The Compaction Behavior of Magnesium-Expanded Natural Graphite Powder Mixtures: Tensile Strengths of Compacted Pellets(Elsevier, 2024) Guden, Mustafa; Betin, Bahattin Berkan; Heptepe, Cafer Can; Gulec, Efe Bati; Yagci, Yavuz Emre; Figen, Aysel Kanturk; Filiz, Bilge CoskunerThe effects of Expanded Natural Graphite (ENG) content, powder mixing method and compaction pressure on the tensile strengths of Magnesium AZ91 (9 wt% Al, 1 wt% Zn and 0.2 wt% Mn) + ENG powder mixture pellets were investigated. The tensile strengths of the pellets increased with an increase in the ENG content and compaction pressure and also with the applied powder ball milling. However, the compaction pressures above 500 MPa resulted in shear banding.