Tension-controlled defect mode localization and energy harvesting in a shunted periodic beam Ahmet Calik Smart Materials and Structures, 2026 This study investigates passive piezoelectric energy harvesting from a tension-tunable defect mode in a periodic Euler–Bernoulli beam. The band structure of the infinite periodic medium is obtained with the transfer-matrix method combined with the Floquet–Bloch condition, whereas the finite defective chain is analyzed with an independent Euler–Bernoulli finite-element model to track the localized defect eigenmode and the corresponding forced response. A single piezoelectric patch spanning the B segment of the defect cell is coupled to a series RL shunt through a Norton-equivalent formulation based on the slope jump across the patch. The numerical examples use a 21-cell chain and a small end-excitation amplitude of w 0 = 10 − 7 m; the responses therefore remain in the linear regime and can be rescaled as V ∝ w 0 and P R ∝ w 0 2 . The results show that axial tension shifts the band-gap edges and the in-gap defect mode together while progressively reducing the degree of localization as the tracked mode approaches a band-gap edge. Under the fixed passive load considered here, the electrical resonance of the RL network lies well above the mechanical band of interest, so the dominant voltage and power peaks in the wideband response do not necessarily coincide with the defect-mode frequency. Nevertheless, the defect mode provides a clear localized mechanical target, and a baseline retuning study shows that changing R alone offers only limited improvement, whereas joint R – L retuning can increase the harvested power by orders of magnitude. These results clarify the distinct roles of mechanical localization and electrical matching in tension-controlled harvesting from periodic beams.
Buckling and near-critical post-buckling of sandwich cylindrical shells with FG-GNP face sheets and an auxetic core under external pressure in a thermal environment: a closed-form approach Ahmet Çalık Continuum Mechanics and Thermodynamics, 2026 This paper presents a closed-form formulation for the linear buckling and near-critical single-mode post-buckling response of sandwich cylindrical shells with functionally graded graphene nanoplatelet (FG-GNP) reinforced face sheets and an auxetic honeycomb core under external pressure and a thermal environment. The shell kinematics follow First-order Shear Deformation Theory (FSDT). Face-sheet properties are obtained from a temperature-dependent Halpin–Tsai scheme combined with a power-law through-thickness gradation, while the auxetic core is represented by equivalent orthotropic constants. A Winkler–Pasternak foundation is included. A single-harmonic Galerkin reduction yields a $$5\\times 5$$ 5 × 5 generalized eigenproblem for both simply supported (SS) and clamped–clamped (CC) boundary conditions; for CC edges, an energy-equivalent axial wavenumber is used to represent end restraint without introducing numerical mode shapes. For the baseline configuration, the minimum critical pressures are approximately 15.86 MPa at (m,n)=(1,10) for SS and 19.96 MPa at (0,11) for CC. Increasing temperature difference reduces $$p_{cr}$$ p cr , whereas the foundation markedly increases it; larger FG index k (less GNP-rich faces) also decreases $$p_{cr}$$ p cr . The Koiter single-mode expansion predicts a stable (hardening) post-buckling branch for the cases examined. The model is intended as a fast analytical screening and benchmarking tool under the stated assumptions.
Static bending and baseline free-vibration assessment of Type-A functionally graded sandwich plates with a homogenized auxetic core Ahmet Çalık Journal of Sandwich Structures and Materials, 2026 This paper examines the static bending response and the baseline free-vibration trends of Type-A functionally graded sandwich plates with Al/ZrO 2 face layers and a homogenized auxetic core. The numerical analysis is carried out within a linear small-strain framework by using a previously verified higher-order shear deformation assumed-strain quadrilateral element, employed here as a computational vehicle rather than as a new finite element development. The free-vibration sweep is restricted to the square simply supported baseline configuration used for literature comparison, whereas the static investigation is extended to four boundary conditions, several slenderness and aspect ratios, multiple gradation exponents, and two layer schemes. The results show that a stiff auxetic core reduces transverse deflection and the top-surface normal stress across all boundary conditions, but increases the monitored shear quantity at the selected edge probe, revealing a clear static stiffness–shear trade-off. A soft auxetic core, in contrast, increases all three monitored static response measures. The extended campaign further shows that increasing the slenderness ratio a / h strongly amplifies deflection, increasing the aspect ratio reduces all monitored static responses, and that the face-sheet gradation interacts with the auxetic core in a metric-dependent manner: more ceramic-dominant faces favor lower deflection and lower monitored shear, whereas more metal-dominant faces reduce the present normalized top-surface stress metric. For the monitored static metrics considered here, the 2–1–2 layer scheme performs less favorably than 1–2–1, particularly for the stiff auxetic core. In the baseline free-vibration sweep, negative core Poisson’s ratio is not uniformly beneficial: frequency gains are concentrated mainly in the stiff-core region and should be interpreted as baseline modal trends rather than as an independently re-benchmarked validation set. Because the core is represented by equivalent isotropic properties, the results are best interpreted as structural-level response maps within the investigated linearized parameter space rather than as topology-specific design rules.
Manufacturability-Aware Multi-Objective Screening of Filament-Wound Type IV Pressure-Vessel Cylindrical Sections Using Dual-Pressure Hashin Constraints Önder Albayrak, Ahmet Çalık Polymer Composites, 2026 A manufacturability‐aware preliminary screening framework is proposed for the straight cylindrical section of filament‐wound Type IV composite pressure vessels. The method reduces the laminate design space before dome‐aware finite‐element and progressive‐damage analyses, rather than replacing full‐vessel burst assessment. Using the public DLR Type IV dataset, the overwrap is evaluated by Classical Lamination Theory under closed‐end membrane loading. Four helical angles and seven wound‐layer thicknesses are optimized with NSGA‐II under controller‐compatible angle and tow‐thickness quantization. The objectives are maximum hoop stress, maximum radial expansion, and cylindrical‐section mass. Feasibility is defined by a dual‐pressure, mode‐separated Hashin screen: fiber integrity is checked at a high‐pressure reference level, whereas matrix integrity is re‐evaluated at service pressure; Tsai–Wu is reported as a passive scalar indicator. For the nominal DLR layup, the model reproduces the experimental hoop strain–pressure slope within 3.8%, while underpredicting the axial slope by 16.5%. The representative knee design achieves , , and . Mass‐matched ablation and robustness studies show that selective hoop‐layer thickening is the dominant improvement mechanism, while the final compromise remains conditional on the prescribed design window.
Effect of Dimensions in Laser Surface Texturing on Cutting Tools Ahmet ÇALIK Mechanika, 2025 A significant part of the costs the companies that produce with the machining method is the cost of the cutting tool. The high cost and the continuous increase in the competition in the sector have pushed the companies operating in this field to work to extend the life of cutting tools. In this study, laser patterning was applied to the surfaces of silicon nitride-based cutting tools, and the most ideal combination was determined by changing the dimensions of the patterning. Before the laser patterning process, an experimental design was created using the Taguchi method and the L9 orthogonal array. The experiments were carried out on a Doosan Puma V550 turning machine, and the chip removal process was carried out dry. Material conforming to the GG25 standard is processed on the turning machine. In the experiments, the widths of the patterns, the spaces between the patterns, and the angles between the lines of the patterns were varied. The wear number of the cutting tools was observed using an Axio Zoom V16 microscope. After all these examinations, the data were collected and the results were compared using the signal-to-noise ratio method. With this comparison, it was seen that the most efficient pattern was 20 μm-300 μm-30°. In addition, it was determined that the most influential factor on cutting tool performance was the angle of the patterns.
Optimizing Support Patch Geometries in Adhesively Bonded Single Lap Joints: A Finite Element Analysis Approach Ahmet Çalık Strojniski Vestnik Journal of Mechanical Engineering, 2025 In recent years, the preference for adhesive bonding over traditional methods like bolted or riveted connections has garnered the attention of researchers. This study employs finite element analysis to optimize the geometry and placement of support patches in adhesively bonded single lap joints, significantly reducing stress concentrations and enhancing joint strength. Initially, a comprehensive finite element analysis was conducted to numerically evaluate the influence of different support patch parameters and their positions on the strength of single lap joints (SLJs). To validate the finite element analyses (FEA), comparisons were made with existing studies in the literature and analytical solutions. The numerical results in this study reveal that the dimensions and placement of the support patch can potentially reduce the load and stress distribution in different regions of the adhesive joint, which could increase its strength.
Innovative Use of Textile Waste for Automotive Applications Mustafa Ozcanli, Berkay Karacor, Belkıs Zervent Ünal, Ahmet Çalik Advances in Science and Technology, 2025 Waste materials (WAS) have recently been recycled into the environment and are materials that come to the fore in terms of both cost and environmental use. The waste material used in this study is a type of material classified as waste in a local textile factory due to the raising process, which cannot be converted back into textile. In this study, the effects of 5%, 10%, 15%, 20%, 25%, 30% and 40% waste raising on the mechanical and physical properties of the composite samples produced by combining them with epoxy were investigated. For comparison purposes, fabric reinforced samples made in previous studies were considered as reference samples. WAS 10 sample is the sample where the tensile strength value reaches its maximum. In the impact test results, the WAS 10 sample absorbed 1.63 times more energy than the WAS5 sample (1.3 J) that came after it, with 2.12 J. The WAS5 sample reached a hardness value of 205.067 in the microhardness test, 3.45% better than the WAS10 sample. Overall, it has been determined that the composite obtained from this waste material, which cannot be recycled into textile products, can be used as an alternative to interior plastics in the automotive industry.
Exploring the efficiency and emission characteristics of hydroxy-boosted canola biodiesel in comparison to traditional diesel fuels Ahmet Çalık Frontiers in Energy Research, 2024 In this research, we experimentally examined how incorporating HHO into blends of 20% canola biodiesel with 80% diesel and 40% canola biodiesel with 60% diesel impacts the engine’s performance and its emission traits. Canola oil, widely used in Europe, served as the biodiesel base. The addition of HHO, recognized for its potential to improve combustion efficiency and reduce emissions which were deteriorated by biodiesel addition. The findings revealed decrement on fuel consumption as 5.74% and 4.43% and rise in thermal efficiencies as 3.92% and 3.97% with HHO addition compared to B20 and B40, respectively. Besides that, CO emissions were reduced significantly up to 35.43%, while CO2 emissions decreased moderately up to 14.93% compared to diesel fuel. On the other hand, biodiesel and HHO addition increased NOx emissions as 49.80%. Utilization of biodiesel and HHO in diesel engines offers a straightforward way to reduce emissions and enhance fuel efficiency, addressing environmental issues and promoting sustainable transportation.
Tension-controlled defect mode localization and energy harvesting in a shunted periodic beam A Çalık Smart Materials and Structures , 2026 2026
Reduced boundary-layer analysis of the isotropic relaxed micromorphic sphere problem: Scaling, collapse behavior, and boundary-condition sensitivity A Çalık, S Akpinar European Journal of Mechanics-A/Solids, 106120 , 2026 2026
Buckling and near-critical post-buckling of sandwich cylindrical shells with FG-GNP face sheets and an auxetic core under external pressure in a thermal environment: a closed … A Çalık Continuum Mechanics and Thermodynamics 38 (2), 21 , 2026 2026
Static bending and baseline free-vibration assessment of Type-A functionally graded sandwich plates with a homogenized auxetic core A Çalık Journal of Sandwich Structures & Materials, 10996362261451559 , 2026 2026
Manufacturability‐Aware Multi‐Objective Screening of Filament‐Wound Type IV Pressure‐Vessel Cylindrical Sections Using Dual‐Pressure Hashin Constraints Ö Albayrak, A Çalık Polymer Composites , 2026 2026
Effect of Dimensions in Laser Surface Texturing on Cutting Tools A Calik Mechanics 31 (4), 428-434 , 2025 2025 Citations: 1
Innovative Use of Textile Waste for Automotive Applications M Ozcanli, B Karacor, B Zervent Ünal, A Çalik Advances in Science and Technology 165, 319-324 , 2025 2025
Optimizing Support Patch Geometries in Adhesively Bonded Single Lap Joints: A Finite Element Analysis Approach A Çalık Strojniški vestnik-Journal of Mechanical Engineering 71 (3-4), 92-102 , 2025 2025 Citations: 2
Optimizing support patch geometries in adhesively bonded single lap joints A Çalik Strojniški vestnik 71 (3/4) , 2025 2025
The effects of using intermittent metal part reinforcement and countersink on the strength of adhesively bonded joints A Çalık, S Akpınar, M Demiral International Journal of Adhesion and Adhesives 130, 103613 , 2024 2024 Citations: 13
Exploring the efficiency and emission characteristics of hydroxy-boosted canola biodiesel in comparison to traditional diesel fuels A Çalık Frontiers in Energy Research 12, 1386440 , 2024 2024 Citations: 4
The effect of geometry on joint strength in adhesively bonded joints with the same adhesive area S Akpinar, İ Hacısalihoglu, A Çalık Mechanics of Advanced Materials and Structures 31 (12), 2635-2647 , 2024 2024 Citations: 28
The effect of fiber length and structure on joint strength in bonded joints with fiber-reinforced composite adhesive A Çalık, S Akpinar International Journal of Adhesion and Adhesives 124, 103365 , 2023 2023 Citations: 23
Combined effects of hydrogen and TiO2 nanoparticle additive on terebinth oil biodiesel operated diesel engine A Çalık, E Tosun, MA Akar, M Özcanlı Science and Technology for Energy Transition 78, 9 , 2023 2023 Citations: 10
Dört Nokta Eğme Yüküne Maruz Yapıştırma Bağlantılarında İç Kademenin Bağlantı Hasar Yüküne Etkisi: Deneysel ve Sayısal Analiz A Çalık, S Akpınar Osmaniye Korkut Ata Üniversitesi Fen Bilimleri Enstitüsü Dergisi 5 (3), 1128 … , 2022 2022 Citations: 1
Influences of Iron Oxide Nanomaterial and Hydrogen Addition into Sunflower Biodiesel/Diesel Powered Diesel Engine Performance and Emissions M Özcanlı, E Tosun, A Çalık Macromolecular Symposia 404 (1), 2100410 , 2022 2022 Citations: 3
Dört Noktalı Eğme Testi Altında Yapıştırıcı ile Birleştirilmiş Bindirme Bağlantısının Deneysel ve Sonlu Elemanlar Analizi S Akpınar, A Çalık Çukurova Üniversitesi Mühendislik Fakültesi Dergisi 36 (3), 649-657 , 2021 2021 Citations: 1
Numerical analysis of elasto-plastic adhesively single step lap joints with cohesive zone models and its experimental verification S Bayramoglu, S Akpinar, A Çalık Journal of Mechanical Science and Technology 35 (2), 641-649 , 2021 2021 Citations: 38
Estimation of depth-dependent material properties of biphasic soft tissues through finite element optimization and sensitivity analysis MK Ün, A Çalık Medical engineering & physics 74, 73-81 , 2019 2019 Citations: 8
Artificial intelligence techniques for the vibration, noise, and emission characteristics of a hydrogen-enriched diesel engine S Yıldırım, E Tosun, A Çalık, İ Uluocak, E Avşar Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 41 … , 2019 2019 Citations: 62
MOST CITED SCHOLAR PUBLICATIONS
Bio-composite materials: a short review of recent trends, mechanical and chemical properties, and applications Ş Yıldızhan, A Çalık, M Özcanlı, H Serin European Mechanical Science 2 (3), 83-91 , 2018 2018 Citations: 163
Using HHO (Hydroxy) and hydrogen enriched castor oil biodiesel in compression ignition engine M Ozcanli, MA Akar, A Calik, H Serin International Journal of Hydrogen Energy 42 (36), 23366-23372 , 2017 2017 Citations: 157
Evaluation of vibration characteristics of a hydroxyl (HHO) gas generator installed diesel engine fuelled with different diesel–biodiesel blends E Uludamar, E Tosun, G Tüccar, Ş Yıldızhan, A Çalık, S Yıldırım, H Serin, ... International Journal of Hydrogen Energy 42 (36), 23352-23360 , 2017 2017 Citations: 101
Determination of vibration characteristics of a compression ignition engine operated by hydrogen enriched diesel and biodiesel fuels A Çalık Fuel 230, 355-358 , 2018 2018 Citations: 83
Artificial intelligence techniques for the vibration, noise, and emission characteristics of a hydrogen-enriched diesel engine S Yıldırım, E Tosun, A Çalık, İ Uluocak, E Avşar Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 41 … , 2019 2019 Citations: 62
Fuel properties, performance and emission characterization of waste cooking oil (WCO) in a variable compression ratio (VCR) diesel engine Ş Yildizhan, E Uludamar, A Çalık, G Dede, M Özcanlı European Mechanical Science 1 (2), 56-62 , 2017 2017 Citations: 52
Failure load prediction of single lap adhesive joints using artificial neural networks E Tosun, A Çalık Alexandria Engineering Journal 55 (2), 1341–1346 , 2016 2016 Citations: 50
İnovasyon, İcat, Teknoloji ve Bilim Kavramları Üzerine D Günay, A Çalık Üniversite Araştırmaları Dergisi 2 (1), 1-11 , 2019 2019 Citations: 49
Effect of adherend shape on stress concentration reduction of adhesively bonded single lap joint A Çalık Engineering Review 36 (1), 29-34 , 2016 2016 Citations: 45
Numerical analysis of elasto-plastic adhesively single step lap joints with cohesive zone models and its experimental verification S Bayramoglu, S Akpinar, A Çalık Journal of Mechanical Science and Technology 35 (2), 641-649 , 2021 2021 Citations: 38
The effect of geometry on joint strength in adhesively bonded joints with the same adhesive area S Akpinar, İ Hacısalihoglu, A Çalık Mechanics of Advanced Materials and Structures 31 (12), 2635-2647 , 2024 2024 Citations: 28
Relevance of inhomogeneous–anisotropic models of human cortical bone: a tibia study using the finite element method K Ün, A Çalık Biotechnology & Biotechnological Equipment 30 (3), 538-547 , 2016 2016 Citations: 24
The effect of fiber length and structure on joint strength in bonded joints with fiber-reinforced composite adhesive A Çalık, S Akpinar International Journal of Adhesion and Adhesives 124, 103365 , 2023 2023 Citations: 23
Effect of adherend recessing on bi-adhesively bonded single-lap joints with spew fillet A Çalik, S Yildirim Sādhanā 42 (3), 317-325 , 2017 2017 Citations: 23
Estimation of crack propagation in polymer electrolyte membrane fuel cell under vibration conditions A Çalık, S Yıldırım, E Tosun International Journal of Hydrogen Energy 42 (36), 23347-23351 , 2017 2017 Citations: 17
The effects of using intermittent metal part reinforcement and countersink on the strength of adhesively bonded joints A Çalık, S Akpınar, M Demiral International Journal of Adhesion and Adhesives 130, 103613 , 2024 2024 Citations: 13
An investigation on the effect of parallel slot in bi-adhesive single lap joints with spew fillet A Çalık, S Yıldırım Journal of Engineering Research 3 (4), 95-110 , 2015 2015 Citations: 12
Effect of Extensometer Usage on Obtaining the Force-Displacement Curve of the Adhesively Single Lap Joint A ÇALIK, S AKPINAR European Mechanical Science 3 (4), 142-146 , 2019 2019 Citations: 11
Combined effects of hydrogen and TiO2 nanoparticle additive on terebinth oil biodiesel operated diesel engine A Çalık, E Tosun, MA Akar, M Özcanlı Science and Technology for Energy Transition 78, 9 , 2023 2023 Citations: 10
Estimation of depth-dependent material properties of biphasic soft tissues through finite element optimization and sensitivity analysis MK Ün, A Çalık Medical engineering & physics 74, 73-81 , 2019 2019 Citations: 8
