Civil Engineering / İnşaat Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/13
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Article Citation - WoS: 6Citation - Scopus: 9Holistic Managements of Textile Wastewater Through Circular, Greener and Eco-Innovative Treatment Systems Developed by Minimal To Zero Liquid Discharge(Elsevier, 2024) Aydıner, Coşkun; Doğan, Esra Can; Mert, Berna Kiril; Pala, Burcu; Demirozlu, Tugba Nur; Balcı, Esin; Narci, Ali OguzhanNew pragmatic and viable solutions to reduce or prevent discharge and to protect reserves are currently among the top-prioritised research for cleaner, circular, and resource-efficient use of industrial waters. So, the development of eco-sustainable water management is essential for green industrial development that will meet versatile and eco-sensitive regulatory standards, especially in water-intensive industries. Textile wastewater was reclaimed in semi to fully closed loops for minimal to zero liquid discharge. Concentrate-mixed wastewater was steadily treated in a hybrid membrane oxidation reactor at 60-80 % synergistic performances with remarkable UF fluxes of 96.4-820 L/m2h without any sludge discharge. Effluent was purified with 90-100 % removals and 20-80 L/m2h in nanofiltration and reverse osmosis. Due to Fenton-specific operation, more handling by ion exchange and neutralisation required to harvest membrane reuse waters and reactor discharge effluents with guaranteed Fe and pH. All-in-one system simulations indicated that high quality reuse waters are produced by 99.9 % efficiency and 98 and 100 % savings in iron and acid but 20-51 % more oxidant through concentrate recycling and regenerant reuse. It was also revealed that reactor effluents can be released to the sea or conventional biological treatment or can be eco-sustainably exploited for in-situ chemical and ex-situ bio-induced recovery of vivianite. This research demonstrates that how textile wastewater can be managed holistically by liquid discharge approaches from 50 % minimal to 99.9 % zero just in two-step, i.e. pretreatment and preconcentration, with consumable minimisation and valuable waste recovery through the eco-innovative systems which are developed as circular, greener, and sludge-free compatible with sustainable development goals.Article Citation - WoS: 3Citation - Scopus: 3Ensemble and Optimized Hybrid Algorithms Through Runge Kutta Optimizer for Sewer Sediment Transport Modeling Using a Data Pre-Processing Approach(Elsevier, 2023) Safari, Mir Jafar Sadegh; Gül, Enes; Dursun, Ömer Faruk; Tayfur, GökmenUncontrolled sediment deposition in drainage and sewer systems raises unexpected maintenance expenditures. To this end, implementation of an accurate model relying on effective parameters involved is a reliable benchmark. In this study, three machine learning techniques, namely extreme learning machine (ELM), multilayer perceptron neural network (MLPNN), and M5P model tree (M5PMT); and three optimization approaches of Runge Kutta (RUN), genetic algorithm (GA), and particle swarm optimization (PSO) are applied for modeling. The optimization and ensemble hybridization approaches are applied in the modeling procedure. For the case of hybrid optimized models, the ELM and MLPNN models are hybridized with RUN, GA, and PSO algorithms to develop six hybrid models of ELM-RUN, ELM-GA, ELM-PSO, MLPNN-RUN, MLPNN-GA, and MLPNN-PSO. Ensemble hybrid models are developed through coupling the ELM and MLPNN models with the M5PMT algorithm. The data pre-processing approach is applied to find the best randomness characteristic of the utilized data. Results illustrate that the RUN-based hybrid models outperform the GA- and PSO-based counterparts. Although the MLPNN-RUN and MLPNN-M5PMT hybrid models generate better results than their alternatives, MLPNN-M5PMT slightly outperforms MLPNN-RUN model with a coefficient of determination of 0.84 and a root mean square error of 0.88. The current study shows the superiority of the ensemble-based approach to the optimization techniques. Further investigation is needed by considering alternative optimization techniques to enhance sediment transport modeling. © 2023 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion ResearchArticle Modeling Plasticity and Damage in Fiber Reinforced Composites by a Crystal Plasticity Based Approach(Elsevier, 2023) Dizman, E. Aybars; Özdemir, IzzetIn very thin ply laminates, delamination failure initiation occurs at much higher stress levels as compared to conventional ply laminates. This results in significant plastic deformation in the matrix accompanied by large fiber rotations. A closer look reveals that microstructure of fiber reinforced composites at large strains do not rotate with the plastic spin induced by the total deformation gradient and therefore inelasticity of such materials requires dedicated constitutive models. This paper focuses on inelastic response of such composites by using a recently proposed crystal plasticity based modeling framework and extents it by a non-local continuum damage mechanics formulation. As opposed to existing works related to composites, adapted crystal plasticity model is formulated and implemented in an implicit manner. To address the initiation and evolution of damage observed at large strains, localizing implicit gradient damage (LIGD) framework is used to degrade the slip resistance and hardening mechanisms on longitudinal and transverse slip systems by means of two separate damage variables. A user element (UEL) subroutine encapsulating all the components of the model is developed and integrated within the commercial finite element solver Abaqus. Capabilities of the model are assessed at material point, ply, and component levels by comparisons with analytical solutions and selected experimental results from the literature.Review Citation - WoS: 42Citation - Scopus: 49Utilization of Waste Materials in the Stabilization of Expansive Pavement Subgrade: an Extensive Review(Elsevier, 2023) Tanyıldızı, Muhammed; Uz, Volkan Emre; Gökalp, İslamExpansive soils, also known as swell-shrink soils, are one of the most problematic soils in highway construction and exhibit significant volume changes by swelling and shrinking while wet and dry, respectively. These changes in soil cause cracks, heaves, differential settlements, and damages to the overlying pavements leading to high maintenance costs. The annual average maintenance cost of structures built on expansive soils ranges from $9 to $15 billion, with 50% of the expenses associated with highways and streets. Chemical stabilization techniques such as cement and lime stabilization are one of the most efficient ways to treat expansive soils. However, there is a need to develop environmentally friendly approaches to stabilize expansive soils due to worldwide growing interest in sustainable developments and concerns about greenhouse gas emissions and climate change. In this context, using waste materials in soil stabilization has been considered an important issue for sustainability concerns. The aim of the current study is to review the relevant studies performed to improve the geotechnical and engineering properties of expansive subgrade soils of pavements by using waste materials arising from industrial, agricultural, and other activities in the last decade. In the organization of this study, characteristics of expansive soils including plasticity, compaction, strength & stiffness, microstructural characteristics, shrink-swell properties, and durability were focused to point out the effect of the waste materials. The overall results obtained throughout the scope of the current study indicated that the use of waste materials in soil stabilization improves the engineering properties of expansive soils, significantly. This paper also provides key information and creates awareness for researchers and sector representatives about sustainable soil stabilization.Article Citation - WoS: 9Citation - Scopus: 13Analysis of Adhesively Bonded Joints of Laser Surface Treated Composite Primary Components of Aircraft Structures(Elsevier, 2023) Martin, Seçkin; Nuhoğlu, Kaan; Aktaş, Engin; Tanoğlu, Metin; İplikçi, Hande; Barışık, Murat; Yeke, Melisa; Türkdoğan, Ceren; Esenoğlu, Gözde; Dehneliler, SerkanThe performance of the adhesively bonded aerospace structures highly depends on the adhesion strength between the adhesive and adherents, which is affected by, in particular, the condition of the bonding surface. Among the various surface treatment methods, as state of the art, laser surface treatment is a suitable option for the CFRP composite structures to enhance the adhesion performance, adjusting the roughness and surface free energy with relatively minimizing the damage to the fibers. The aim of this study is the validation and evaluation of the adhesive bonding behavior of the laser surface-treated CFRP composite structures, using the finite element technique to perform a conservative prediction of the failure load and damage growth. Such objectives were achieved by executing both experimental and numerical analyses of the secondary bonded CFRP parts using a structural adhesive. In this regard, to complement physical experiments by means of numerical simulation, macro-scale 3D FEA of adhesively bonded Single Lap Joint and Skin-Spar Joint specimens has been developed employing the Cohesive Zone Model (CZM) technique in order to simulate bonding behavior in composite structures especially skin-spar relation in the aircraft wing-box.Book Part Citation - Scopus: 4Application of Fuzzy Logic in Water Resources Engineering(Elsevier, 2022) Tayfur, GökmenThis chapter introduces the fundamentals of fuzzy logic (FL), fuzzy sets, and fuzzy model components such as the fuzzification, the fuzzy rule base, the fuzzy inference engine, and the defuzzification. The processes of the fuzzy model components are presented by working on the examples from the water resources engineering application problems. This chapter also discusses the merits and the shortcomings of the fuzzy modeling. Hydrological processes have inherent source of uncertainty, for which the fuzzy set theory can be an effective solution tool. © 2023 Elsevier Inc. All rights reserved.Book Part Citation - Scopus: 1Developments in Sediment Transport Modeling in Alluvial Channels(Elsevier, 2022) Tayfur, GökmenThis chapter discusses the developments in the mathematical modeling of sediment transport dynamics in alluvial channels. Starting with early experimental and empirical studies, it goes on to treating the processes in 1D, 2D, and 3D uniform sediment transport. Finally, it describes the treatment of the processes in 3D nonuniform sediment transport considering turbulence effects. While introducing the advancements in mathematical modeling of the dynamics, the chapter also discusses the outstanding issues like the treatment of the particle fall velocity, the particle velocity, and sediment transport rate function. © 2023 Elsevier Inc. All rights reserved.Book Part Citation - Scopus: 3Real-Time Flood Hydrograph Predictions Using Rating Curve and Soft Computing Methods (ga, Ann)(Elsevier, 2022) Tayfur, GökmenThis chapter introduces hydraulic and hydrologic flood routing methods in natural channels. It details hydrological flood routing methods of the Rating Curve and Muskingum. Based on the rating curve method (RCM), it presents real-time flood hydrograph predictions using the genetic algorithm (GA-based RCM) model. In addition, it presents how to make real-time flood hydrograph predictions using the artificial neural network (ANN). The chapter briefly introduces the basics of GA and details how to calibrate and validate the GA-based RCM model using measured real-time flood hydrographs. Similarly, after giving the basics of ANN, it shows how to train and test the ANN model using measured hydrographs. Real hydrograph simulations by the RCM, GA-based RCM, and ANN are presented, and merits of each model are discussed. © 2023 Elsevier Inc. All rights reserved.Letter Reply To the Discussion on “the Modified Vlasov Model on a Nonhomogeneous and Nonlinear Soil Layer”(Elsevier, 2023) İşbuğa, Volkan; Çerezci, Mehmet; Aşık, A. ZülfüThe discussion suggests that the paper has left out four references (Haldar and Basu, 2013; Haldar and Basu, 2016; Elhuni and Basu, 2019; Elhuni and Basu, 2021), and the research work in the paper is not new. The authors would like to state that the literature review in the paper was kept as vast as and to stay as close as possible to the model given in the paper, which is a gross model. The study aimed to offer a method using a previously developed formulation for accounting for soil nonlinearity (Vallabhan and Das, 1988,1991a,1991b). The primary concentration in the literature was given to the most relevant works on the modified Vlasov model that employs the same concept for the solution method and algorithm, which lays the foundation of the paper (Vallabhan and Das 1988,1991a,1991b; Asik, 1999; Asik and Vallabhan,2001). On the other hand, as clearly indicated in the study, the literature in the field is extensive, including the works suggested by the discussion. Despite the author’s efforts, it was not possible to review or/ and mention all the works previously conducted to solve the problem with different approaches. In this respect, the previous studies by Haldar and Basu (2013) and Elhuni and Basu (2019) mentioned in the discussion are not directly related to the problem considered in the paper. Haldar and Basu (2016) proposed a framework incorporating the finite difference and the finite element methods.Article Citation - WoS: 11Citation - Scopus: 12An Improved Passive Tuned Mass Damper Assisted by Dual Stiffness(Elsevier, 2023) Roozbahan, Mostafa; Turan, GürsoyA tuned mass damper (TMD) is one of the oldest and most commonly used passive control devices attached to structures to absorb lateral loads of energy from main systems. In the last decades, several novel tuned mass dampers have been designed to increase the performance of TMDs in decreasing the structural responses during excitation vibrations. Moreover, several formulations and numerical optimization methods have been developed to optimize the TMDs parameters. This paper proposes a novel passive tuned mass damper with dual stiffness (DSTMD). The DSTMD includes mass, primary and secondary springs, dashpot, and motion limiting chamber. The performance of DSTMDs depends on their properties such as mass, primary and secondary stiffness, damping coefficient, and the length of the motion limiting chamber. Thus, a metaheuristic optimization algorithm, called the Mouth Brooding Fish algorithm, was used to optimize the DSTMDs parameters. The effectiveness of the optimum DSTMD on two different linear ten-story structures under several earthquakes has been studied and compared with the effectiveness of classical optimum TMDs. According to the study, optimum DSTMDs generally show better effects for certain excitations, and as an average performance, they are superior compared to the classical optimum TMDs in reducing maximum displacement of the buildings. At last, structural yielding is considered, and the performance analysis on this structure shows that the DSTMD has a superior effect in reducing the maximum displacement and is among the best methods for the calculated absolute yielding amount.