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    Investigation of the Effect of Unit Cell Type on the Mechanical Properties of Lattice Structures by Dynamic Point Tracking
    (Springer, 2026) Akbay, Ozgun Ceren; Bahce, Erkan
    Additive manufacturing enables the fabrication of lattice structures with complex geometries and customizable mechanical properties. As the capabilities of this technology expand, understanding and optimizing the mechanical performance of different lattice topologies has become increasingly important. In this study, the effect of unit cell variation on the mechanical performance of various lattice topologies (Octet, Dode Medium, Dode Thick, Diamond, Rhombi Octa Light, Body Diagonal With Nodes, and Rhombic Dodecahedron) was systematically investigated. Using the dynamic point tracking method, displacement values at the top left, top right, and center points of each model were measured to assess deformation behavior. The Body Diagonals With Nodes model exhibited the highest displacement values (top left: 43.83 pixels, top right: 46.07 pixels, center: 40.31 pixels), indicating greater deformation compared to the other models. In contrast, the Rhombic Dodecahedron model showed minimal and symmetric displacement (4.24 pixels at both top points), reflecting a more stable structure. These findings demonstrate the critical role of unit cell geometry in determining the mechanical response of lattice structures and provide valuable insights for optimizing lattice designs in advanced engineering applications where stability and deformation resistance are essential.
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    Mechanical characterization of lattice structure produced by additive manufacturing under torsion and compression
    (Sage Publications Ltd, 2024) Akbay, Ozgun Ceren; Ozdemir, Burak; Bahce, Erkan; Emir, Ender; Uysal, Mine Uslu
    In the present paper, the torsion and compression behaviors of lattice structures were studied. The PLA (Polylactic Acid) materials were used in assembly and produced by additive manufacturing method. The structure and lattice behaviors were investigated by Digital Image Correlation (DIC) system during experimental study. Models created using three different unit cell model as Trunch Octa Dense, Trunch Octa Light, Body Diagonals With Nodes and two different, 70 mm and 140 mm, total length size. The influence of the unit cell model, cell size on the strength of the structure were studied by compression and torsion experiments. The maximum compressive stress and maximum torsion were obtained and their deformations were presented. The highest maximum torque was determined in Body Diagonals With Nodes cell model and 140 mm due to the fact that the cell model structure compatible with torsion. The highest compressive stress was determined in Trunch Octa Light cell model and 140 mm cell length. Graphical Abstract
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    Production and Cleaning of Lattice Structures Used in the Space and Aerospace Industry with Metal Additive Manufacturing Method
    (Springer, 2022) Akbay, Ozgun Ceren; Bahce, Erkan; Uysal, Alper; Gezer, Ibrahim
    Thanks to additive manufacturing, the use of lattice structures in aviation and space industry, especially heat exchangers, fuel nozzles and turbo machines located at the front of airplanes has increased. The production of computer-designed parts with the desired precision and geometry is important for concepts such as assembly, wear and surface properties. Problems encountered in selective laser melting (SLM) such as porosity, powder particle adhesions, affect assembly and surface properties. For this reason, cleaning is inevitable in sensitive systems used in the aerospace industry to have ready-to-use products after production or to prevent dust particles from breaking and causing problems in the workflow. To this purpose, chemical washing process was applied to improve the surface quality of the lattice structures and the healing effects of the acids used on the surfaces were investigated. In the experiment, nine lattice structures were produced from CoCr alloy and the effects of three different acid solutions prepared using hydrofluoric acid, nitric acid, sulfuric acid and hydrochloric acid on surface cleaning capacity were examined. The changes in the models immersed in the acid solution using the controlled immersion method for 180 seconds are presented comparatively. As a result of the experiment, it was seen that especially the solution containing hydrofluoric acid contributed to the improvement of the surface properties after production.
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    Production of natural source nanocrystalline cellulose and performance comparison with industrial cellulose
    (Sage Publications Ltd, 2025) Akbay, Ozgun Ceren; Bahce, Erkan; Koytepe, Suleyman; Kanmaz, Hilal; Hayaloglu, Ali Adnan
    In this study, date kernel waste was used to produce nanocrystalline cellulose and the resulting material's properties were systematically compared with those of commercially available industrial cellulose. The extraction of cellulose from date kernels was performed using a Soxhlet apparatus with an ethanol-hexane mixture under continuous reflux for 8 h to remove oils and soluble impurities. Subsequently, an alkaline treatment with 4% NaClO at 80 degrees C for 3 h was applied to eliminate lignin and hemicellulose. The resulting material was washed, neutralized, and dried. Acid hydrolysis was then conducted, followed by centrifugation and neutralization, and the NCC suspension was freeze-dried to obtain a powder. For comparative purposes, a single industrial cellulose CNC was used as a reference. This commercial CNC is characterized by a white color, a density of 1.49 g/cm3, a dispersed powder particle size below 150 nm at 2% (w/w), and a high crystallinity index of 92% (XRD). Additionally, among various industrial celluloses with different price and quality segments available in the market, this product was selected as the most cost-effective option, with a price of 2 euros/kg. This selection process enhanced the rigor of the comparative analysis by ensuring that the reference material represented both high quality and economic feasibility. The morphological, chemical, and thermal properties of both NCC and industrial CNC were characterized using various analytical techniques. SEM showed that the nanostructure of the NCC made from date kernel waste had an average width of 10-20 nm and a length of 300-900 nm. EDX demonstrated homogeneous elemental distribution. XRD analysis showed that NCC has a high level of crystallinity, while DTA and DSC showed that NCC's thermal stability is similar to that of commercial CNC. FTIR confirmed the preservation of the pure cellulose structure, and TGA gave us information about the degradation stages and initial degradation temperatures of both materials. The results show that using Soxhlet extraction and other chemical methods works well to turn date kernel waste into valuable nanocellulose products. The NCC obtained shows significant potential as a sustainable and cost-effective alternative to industrial cellulose for applications in biomedical fields, composite materials, and eco-friendly packaging.