Browsing by Author "Dincer, A. Ersin"

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A Fully Coupled Numerical Model for Unbonded Post-Tensioned Timber Structures
(Springer, 2024) Dincer, A. Ersin; Demir, Abdullah
The paper presents a fully Lagrangian mesh-free solver to simulate the dynamic behavior of post-tensioned timber structures. Weakly Compressible Smoothed Particle Hydrodynamics (SPH) is employed to model both the timber and the tendon. An efficient and simple coupling method between the timber and the tendon is proposed by considering the numerical stability. Besides, the same coupling algorithm is used to model the interaction between column and beam elements. Although the column is treated as rigid in the simulations, the coupling algorithm accounts for the initial compression of the column resulting from post-tensioning. For the verification of the code for solids and material nonlinearity of timber, benchmark problems available in the literature are used. Finally, the solver's capability is demonstrated through dynamic analysis of post-tensioned timber structures. The solutions obtained for all the cases are in good agreement with the experimental and theoretical data, which indicates the applicability and accuracy of the solver.
Citation - WoS: 4
Citation - Scopus: 3
Experimental and Numerical Investigation of Hyper-Elastic Submerged Structures Strengthened With Cable Under Seismic Excitations
(Taylor & Francis Ltd, 2022) Dincer, A. Ersin
This study presents dynamic responses of submerged highly elastic structures, strengthened with cable elements and the fluid interacting with the structure. For this purpose, fluid and structure are modelled with smoothed particle hydrodynamics and finite element methods, respectively. The interaction is satisfied with contact mechanics. In order to simulate the cable, a finite element model with a two-node cable element is used. The stiffness obtained from the cable is added to the structure and the whole fluid-structure system is solved together. The novel contribution of the present study is the coupling a two-node cable element model with the fluid-structure interaction method. In order to validate the numerical method, a set of novel experiments is carried out. In the experiments, cable elements are attached to an elastic structure that is placed in a water tank. Near-fault and earthquake excitations are applied to the tank and the displacement of the structure and the free surfaces of the water are recorded. All the results show that the proposed two-dimensional numerical model is capable of modelling the submerged elastic structure strengthened with the cable under the seismic excitations.
Citation - WoS: 16
Citation - Scopus: 17
A Novel Procedure for the AHP Method for the Site Selection of Solar PV Farms
(Wiley, 2024) Demir, Abdullah; Dincer, A. Ersin; Yilmaz, Kutay
This study proposes a novel approach to enhance the analytic hierarchy process (AHP) for the selection of suitable sites for solar photovoltaic (PV) farms. This approach is particularly beneficial when it is possible to establish a predefined objective relation in the final weights of the AHP method. The methodology focuses on achieving this predefined relation introducing a systematic revision of the constants of related constraints. In this study, the costs of constructing a unit transmission line and road in the Kayseri Province are objectively related, and the initial constant matrix of the AHP method is iteratively revised until the relation of the final weights converges to the predefined one. The suitability of solar PV farm locations is classified into five classes, revealing approximately 28% (40-100% of suitability) of the province as favorably suitable and designating about 67% as restricted zones. The findings reveal notable distinctions between the revised weights and those derived from the conventional AHP method. The disparity in weights for various constraints varies from 13.5% to 7.2%. Consequently, the alterations in the area of suitability regions range from 3.4% to 50%. The revision of AHP weights results in a reduction in higher-suitability areas, coupled with a significant expansion in the region exhibiting lower suitability. Notably, the extent of change in the suitability map increases when the difference in ratios between two criteria obtained from the AHP and the predefined objective relation is high. The proposed method demonstrates its applicability in regions like Kayseri where an objective relation between criteria can be established. Given the inherent subjectivity of the AHP method, the proposed procedure becomes essential to attain more objective weights. Since the methodology objectively adjusts weights based on known ratios, it increases the accuracy and reliability of site selection studies.
Citation - WoS: 3
Citation - Scopus: 3
Application of Smoothed Particle Hydrodynamics to Structural Cable Analysis
(MDPI, 2020) Dincer, A. Ersin; Demir, Abdullah
In this study, a numerical model is proposed for the analysis of a simply supported structural cable. Smoothed particle hydrodynamics (SPH)-a mesh-free, Lagrangian method with advantages for analysis of highly deformable bodies-is utilized to model a cable. In the proposed numerical model, it is assumed that a cable has only longitudinal stiffness in tension. Accordingly, SPH equations derived for solid mechanics are adapted for a structural cable, for the first time. Besides, a proper damping parameter is introduced to capture the behavior of the cable more realistically. In order to validate the proposed numerical model, different experimental and numerical studies available in the literature are used. In addition, novel experiments are carried out. In the experiments, different harmonic motions are applied to a uniformly loaded cable. Results show that the SPH method is an appropriate method to simulate the structural cable.
Citation - WoS: 16
Citation - Scopus: 19
Effect of Urbanization on Surface Runoff and Performance of Green Roofs and Permeable Pavement for Mitigating Urban Floods
(Springer, 2024) Ozturk, Sevki; Yilmaz, Kutay; Dincer, A. Ersin; Kalpakci, Volkan
Floods are increasingly becoming a significant concern due to climate change, global warming, and excessive urbanization. The Intergovernmental Panel on Climate Change (IPCC) has projected that global warming will continue to contribute to more frequent and severe floods and hydrological extremes. In response to these challenges, nature-based solutions (NBSs) have gained recognition as effective approaches to mitigate the adverse impacts of floods by focusing on ecosystem conservation, restoration, and sustainable utilization of natural resources. This study examines a flood that occurred in the Erkilet District of Kayseri, T & uuml;rkiye on September 22, 2022, as a result of intense rainfall. It involves a thorough on-site investigation to assess the hydraulic, hydrologic, and geotechnical attributes of the study area. The findings from the field study indicate that the primary cause of the flood is attributed to excessive urbanization. To further analyze the impact of urbanization, a hydraulic model is developed considering both the physical and topographical conditions of the study area for both the year 2006 and 2022. The simulation results reveal that the extent of inundation area and water depth has increased significantly due to the excessive urbanization that occurred within a 16-year period. Additionally, the effectiveness of green roofs and permeable pavements as NBSs to mitigate urban flooding is explored. The implementation of green roofs and permeable pavements shows promising results, reducing the adverse effects of urban floods by 3% to 8%, depending on their specific locations and configurations. However, the results suggest that NBSs alone cannot fully prevent floods so they should complement gray infrastructure. The novelty of the study lies in its ability to demonstrate the impact of urbanization and the effectiveness of nature-based solutions in mitigating flood extent based.
Citation - WoS: 18
Citation - Scopus: 21
Investigation of the Sloshing Behavior Due to Seismic Excitations Considering Two-Way Coupling of the Fluid and the Structure
(MDPI, 2019) Dincer, A. Ersin
Sloshing behavior due to near-fault type and earthquake excitations of a fluid in a tank having a highly deformable elastic structure in the middle was investigated experimentally and numerically in this paper. In the numerical model, fluid was simulated with smoothed particle hydrodynamics (SPH) and structure was simulated with the finite element method (FEM). The coupling was satisfied with contact mechanics. The delta-SPH scheme was adapted to lower the numerical oscillations. The proposed fluid-structure interaction (FSI) method can simulate the violent fluid-structure interaction problem successfully. The effects of near-fault type and earthquake excitations on free-surfaces of fluid and the elastic structure are presented.
Citation - WoS: 12
Citation - Scopus: 16
Debris Flow Modelling and Hazard Assessment for a Glacier Area: A Case Study in Barsem, Tajikistan
(Springer, 2023) Yilmaz, Kutay; Dincer, A. Ersin; Kalpakci, Volkan; Ozturk, Sevki
This study analyses a previous debris flow hazard as a consequence of emerging risks related to climate and regional physical changes. In addition to the increasing flood frequencies, there is an increasing risk of mud or debris flow due to increasing temperature and heavy precipitation resulting in glacier melting. One of the most recent dramatic examples of the debris flow incident took place in Barsem, Tajikistan, in 2015. As a result of heavy precipitation and excess temperature, the melting of glaciers caused debris flow which ended up with a catastrophic damage at Barsem Town. In this study, a methodology for modelling debris flow and related hazard is developed by examining the 2015 incident in detail with a commercially available software, Hydrological Engineering Centre-River Analysis System (HEC-RAS). Simulations and hazard assessment of the incident suggest that assessment of debris flow hazard can be implemented similar to flood hazard. Moreover, it is seen that debris flow inundation area can be predicted accurately by low-resolution free-source digital elevation models (DEMs), while in the present work they could not predict the debris flow hazard assessment accurately. Sensitivity results also reveal that free-source DEMs with higher resolutions do not necessarily give better predictions than free-source DEMs with lower resolutions.