Bartın Üniversitesi Araştırma ve Akademik Performans Sistemi
DSpace@Bartın, Bartın Üniversitesi’nin bilimsel araştırma ve akademik performansını izleme, analiz etme ve raporlama süreçlerini tek çatı altında buluşturan bütünleşik bilgi sistemidir.
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Yıllara Göre Dağılım
Türlere Göre Dağılım
Güncel Gönderiler
Öğe Türü: Yayın , Experimental investigation of fatigue behavior of reinforced concrete beams strengthened with CFRP1(2026) Erbaş, Yaşar; Erbaş, Yaşar; Mühendislik Mimarlık ve Tasarım Fakültesi, İnşaat Mühendisliği BölümüReinforced concrete beams used in bridges, viaducts, and industrial structures are subjected to repeated moving loads throughout their service life, which may lead to fatigue-induced deterioration in structural strength and bond performance. Moreover, external factors such as corrosion, temperature fluctuations, and overloading accelerate the adverse effects of fatigue, leading to severe damage and even sudden failure at load levels below the ultimate load-carrying capacity. In recent years, carbon fiber-reinforced polymer (CFRP) materials have been widely adopted for strengthening reinforced concrete beams owing to their high strength-to-weight ratio, excellent corrosion resistance, ease of application, and negligible increase in the member's cross-sectional dimensions. In this study, the fatigue behavior of reinforced concrete beams strengthened with externally bonded CFRP strips was experimentally investigated. A total of four 1/3-scale reinforced concrete beam specimens, with a cross-section of 100 × 150 mm and a length of 1200 mm, were fabricated. The tensile reinforcement consisted of 2Ø10 longitudinal bars, while the compression reinforcement comprised 2Ø4 longitudinal bars. Shear reinforcement was provided using Ø4 stirrups spaced at 200 mm. One unstrengthened specimen was tested under monotonic static loading, while another unstrengthened specimen was tested under cyclic fatigue loading as the reference specimen. The remaining two specimens were strengthened with externally bonded CFRP strips and subsequently tested under fatigue loading. The experimental variable was selected as the spacing of the CFRP strips. Accordingly, CFRP strips with a width of 50 mm were applied at a spacing of 150 mm and 200 mm. All specimens were tested under a four-point bending test. The experimental results showed that the unstrengthened reference specimen reached an ultimate load capacity of 23.8 kN under static loading. The second reference specimen, subjected to cyclic fatigue loading between 10 and 18 kN, collapsed after 1800 loading cycles. In contrast, the CFRP-strengthened specimens were tested under a substantially higher cyclic load range of 16-32 kN, corresponding to approximately 78% higher maximum load than that applied to the reference specimen tested under fatigue loading. Under these loading conditions, the specimen strengthened with 150 mm strip spacing collapsed after 1480 cycles, whereas the specimen with 200 mm strip spacing collapsed after only 265 cycles. The findings demonstrate that reinforced concrete beams strengthened with externally bonded CFRP strips can sustain significant fatigue performance even under cyclic loading levels that exceed the monotonic static load-carrying capacity of the reference specimen. Furthermore, reducing the spacing between CFRP strips markedly improved the fatigue life of the strengthened beams.Öğe Türü: Yayın , Nonlinear finite element investigation of 3D-printed concrete wall panels under diagonal compression(26th International Istanbul Scientific Research Congress on Life, Engineering, Architecture and Mathematical Sciences, 2026) Erbaş, Yaşar; Erbaş, Yaşar; Mühendislik Mimarlık ve Tasarım Fakültesi, İnşaat Mühendisliği BölümüThis study investigates the in-plane behavior and damage mechanisms of three-dimensional (3D) printed concrete wall panels with dimensions of 600×600×150 mm using nonlinear finite element analysis. A three-dimensional finite element model of the wall panel was developed in ABAQUS. C3D8R solid elements with an approximate element size of 10 mm were employed in the model. The nonlinear behavior of concrete was simulated using the Concrete Damage Plasticity (CDP) model, which accounts for tensile cracking, compressive crushing, stiffness degradation, and plastic deformation. The specimen geometry, arrangement of the printed layers, interlayer interface behavior, boundary conditions, and diagonal loading configuration were incorporated into the finite element model. The interaction between the printed concrete layers was modeled using tie constraints defined between the surfaces of adjacent layers. Diagonal loading was applied under displacement control through the corner region of the wall panel. The load-carrying capacity and damage distributions obtained from the numerical analyses were compared with the results of an experimental study available in the literature. In addition, crack initiation regions, crack propagation paths, and critical damage zones were evaluated based on the damage distributions obtained from the numerical analysis. The finite element model successfully reproduced the experimental ultimate load-carrying capacity and the characteristic damage mechanism observed in the wall panel. Based on the experimental results, the relative error in the ultimate load-carrying capacity predicted by the numerical model was 5.75%. The findings demonstrate that the developed finite element model provides a reliable approach for the numerical assessment of the nonlinear in-plane behavior and damage evolution of 3D-printed concrete wall panels under diagonal loading. Furthermore, the present study may provide a basis for future numerical investigations in which interlayer interface behavior is examined in deep detail.Öğe Türü: Yayın , Wijsman statistical, strong cesaro, and ideal convergence of closed sets in idempotent bicomplex metric spaces(Wiley, 2026) Gargouri, Ameni; Gürdal, Mehmet; Kişi, Ömer; Mhemdi, Abdelwaheb; Kişi, Ömer; Fen Fakültesi, Matematik BölümüThis paper studies generalized Wijsman convergence for sequences of nonempty closed subsets of an idempotent bicomplex metric space. Let rho = d(1)e(1) + d(2)e(2), where d(1) and d(2) are metrics on the same underlying set X. For a nonempty subset A of X, we define the bicomplex point-to-set distance by rho(x, A) = d(1)(x, A)e(1) + d(2)(x, A)e(2). This definition retains the idempotent decomposition of the metric and allows the convergence of closed sets to be studied through the two component distance functions. For an exponent sequence p = (p(k)) satisfying 0 < inf(k)p(k) <= sup(k)p(k) < infinity, we introduce Wijsman statistical convergence, Wijsman strong Cesaro convergence of power type p, Wijsman I -convergence, and Wijsman I K -convergence. We prove that each of these notions is equivalent to the simultaneous validity of the corresponding Wijsman convergence conditions with respect to the component metrics d(1) and d(2). As consequences, ordinary Wijsman convergence implies Wijsman statistical convergence, while Wijsman strong Cesaro convergence implies Wijsman statistical convergence. The converse implication holds when the component distance deviations are pointwise bounded. For admissible ideals I and K , we show that W - I p K -convergence implies W - I p -convergence for every sequence if and only if K subset of I . We also compare the componentwise bicomplex point-to-set distance with the point-to-set distance determined by the associated real metric. Examples show that these two constructions need not agree and that the principal implications obtained in the paper cannot, in general, be reversed.Öğe Türü: Yayın , When democracy delivers: Threshold effects in governance quality(Sage Publications Inc., 2026) Topcuoğlu, Erdi; Topçuoğlu, Erdi; İktisadi ve İdari Bilimler Fakültesi, Siyaset Bilimi ve Kamu Yönetimi BölümüThis study investigates the relationship between democratic institutionalization and governance quality through a measurement-oriented approach using a panel dataset of 146 countries from 2013 to 2023. Drawing on democracy scores from the Economist Intelligence Unit (EIU) and governance indicators from the Worldwide Governance Indicators (WGI), the analysis examines how variations in democratic development correspond to changes in six dimensions of institutional performance. Although both datasets assess aspects of political institutionalization, they originate from distinct conceptual frameworks, the EIU focusing on electoral and participatory dimensions of democracy, and the WGI emphasizing administrative and legal governance outcomes. Fixed-effects and piecewise regression analyses reveal that governance improvements accelerate beyond mid-range democracy levels, suggesting a threshold effect in institutional performance. Bootstrap confidence intervals confirm the robustness of these non-linear patterns. These findings contribute to the literature on institutional quality by clarifying the empirical linkages and distinctions between democratic development and governance, demonstrating that their alignment reflects co-evolving, but not redundant dimensions of political modernization.Öğe Türü: Yayın , Using the snowIRT module in jamovi for rasch analysis: A tutorial for counseling research(Routledge Journals, Taylor & Francis Ltd, 2026) Dünya, Beyza Aksu; Demir, Mehmet Can; Dünya, Beyza Aksu; Demir, Mehmet Can; Eğitim Fakültesi, Eğitim Bilimleri BölümüAlthough Rasch modeling is widely used in counseling and psychological research, its practical application is often constrained by technical complexity and limited accessibility of existing software. This study demonstrates how to conduct and interpret Rasch-based analyses using the snowIRT module in the Jamovi statistical environment. To address this gap, the tutorial offers a clear, step-by-step guide within a user-friendly, menu-driven interface. Using a depression scale dataset as an example, it presents key procedures, including model estimation, model comparison, item diagnostics, category functioning, graphical outputs, and person-level evaluation. It also explains how to interpret Rasch results in applied measurement contexts. Furthermore, the study connects Rasch outputs with Messick's unified validity framework, illustrating how such evidence supports multiple aspects of construct validity. Overall, the tutorial provides an accessible, theoretically grounded resource that facilitates broader use of Rasch modeling in counseling and social science research and improves methodological transparency for researchers across disciplines.
