Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Investigating the Effects of Functionalized Single Wall Carbon Nanotubes on the Cure Behavior of a Carbon/Epoxy Prepreg System by an Optimized Parameter Approach(Wiley, 2025) Oz, Murat; Uz, Yusuf Can; Tanoglu, Gamze; Tanoglu, Metin; Barisik, MuratCarbon/Epoxy composite materials are used in a wide range of applications due to their superior performance. However, their properties are strongly related to cross-linking reactions occurring during the curing process, and a prior estimation of curing parameters is the key to manufacturing the desired material. This study builds a mathematical model to solve the inverse kinetic problem based on differential scanning calorimetry data and later presents its use in curing experiments. The method derived (Gamze-Murat-Neslisah (GMN) approach) determines the pre-exponential and activation energy of the curing process. Later, an extended experimental study was performed. Functionalized single-wall carbon nanotubes (F-SWCNTs) were prepared by oxidizing their surface with carboxyl to enhance the dispersion of the nanoparticulates. The epoxy resin systems were modified with 0.05%, 0.1%, and 0.2% wt. F-SWCNTs, which were impregnated on carbon fibers (CFs). The curing behavior was studied, cure kinetic parameters were determined, and the thermal behavior was characterized. Differential scanning calorimetry (DSC) data sets for CF/epoxy prepregs containing F-SWCNTs were used for the verification of the proposed method. It was found that the GMN approach is in good agreement with the experimentally measured data for all kinetic parameters. The addition of F-SWCNTs increased the material's curing efficiency as the CNTs enhanced heat transport in composites, reducing the activation energy. The results obtained from the GMN algorithm were also found in good agreement with the well-known Kissinger-Akahira-Sunose (KAS) and Kissinger methods, while the current GMN method revealed itself as an accurate algorithm to obtain the activation energy.Article Influence of Intra-Ply Discontinuities on the Mechanical Behavior of Continuous E-Glass Fiber Reinforced Composites(Sage Publications Ltd, 2024) Kilicoglu, Ahmet Suha; Tanoglu, Metin; Bilmez, Sinan Ali; Gunes, Mehmet Deniz; Erdogan, Hakan SalihThis study examines how structural discontinuities created during production affect glass fiber-reinforced composite plates. Due to geometrical constraints, the composite microstructure's discontinuities can be categorized as inter-ply and intra-ply. Material testing was conducted at the coupon level as an initial step to ascertain material characteristics. Two full-scale models of intra-ply composite samples were manufactured by employing layers of glass fiber-reinforced prepregs. Discontinuities were generated in the samples using a computer numeric control cutter and then manually applied. The discontinuities' impact on the composite laminate's mechanical properties was assessed through full-scale pieces using three-point bending quasi-static tests. Servo-hydraulic actuators were used to conduct tests on the items. The experimental test results were compared with CAE analysis predictions by evaluating sectional fiber volume fraction. The characteristics of local discontinuities were analyzed using a microscope to enhance the findings of the CAE model. This comprehensive approach offers insights into the intricate connection between internal structural inconsistencies and the mechanical properties of continuous glass fiber-reinforced materials. It supports optimizing composite manufacturing processes and improves composite parts' structural reliability. Dislocation areas were found to result in the formation of resin-rich zones in this investigation. The exothermic curing process in the component's zones results in elevated temperatures, leading to a color change in the resin from clear to yellow. The yellow areas are easily recognizable and show decreased mechanical durability.Review Citation - WoS: 21Citation - Scopus: 21Advancement in the Modeling and Design of Composite Pressure Vessels for Hydrogen Storage: a Comprehensive Review(Mdpi, 2024) Bouhala, Lyazid; Karatrantos, Argyrios; Reinhardt, Heiner; Schramm, Norbert; Akin, Beril; Rauscher, Alexander; Tanoglu, MetinThe industrial and technological sectors are pushing the boundaries to develop a new class of high-pressure vessels for hydrogen storage that aim to improve durability and and endure harsh operating conditions. This review serves as a strategic foundation for the integration of hydrogen tanks into transport applications while also proposing innovative approaches to designing high-performance composite tanks. The goal is to offer optimized, safe, and cost-effective solutions for the next generation of high-pressure vessels, contributing significantly to energy security through technological advancements. Additionally, the review deepens our understanding of the relationship between microscopic failure mechanisms and the initial failure of reinforced composites. The investigation will focus on the behavior and damaging processes of composite overwrapped pressure vessels (COPVs). Moreover, the review summarizes relevant simulation models in conjunction with experimental work to predict the burst pressure and to continuously monitor the degree of structural weakening and fatigue lifetime of COPVs. Simultaneously, understanding the adverse effects of in-service applications is vital for maintaining structural health during the operational life cycle.Article Citation - WoS: 7Citation - Scopus: 7Development of Resin-Based Dental Composites Containing Hydroxyapatite and Zirconia Nanoparticles(Wiley, 2024) Taskiran, Senagul Tunca; Tanoglu, Metin; Cerci, Nazife; Cevahir, Aref; Damar, Ceren Turkdogan; Unver, Elcin; Aktas, Mustafa IlkerIn clinical applications, resin-based dental composites primarily face challenges with fractures and secondary caries. To overcome these issues, the physical characteristics of dental composites, especially mechanical properties, need to be improved. Hydroxyapatite (HA), present in the structure of the teeth, is preferred due to its biological properties, and zirconia (ZrO2) nanoparticles are known to enhance the mechanical properties of this type of composites. The aim of this study is to develop resin-based dental composites containing HA and ZrO2 nanoparticles. The study also aims to explore the synergistic effect of these two nanoparticles on the physical properties of the developed composites. Composites with nine different compositions were prepared by mixing the components with the help of a mortar mill. The flexural and compressive strength, polymerization shrinkage, depth of cure and water sorption, and solubility properties of the prepared composites have been investigated. All composites have been found to meet the requirements of ISO 4049 standard. Among them, composite containing 5 wt. % HA and 1 wt. % ZrO2 (H5Z1) has exhibited the highest flexural strength with an increase of 58% compared to the control sample, and composite containing 3 wt. % HA and 2 wt. % ZrO2 (H3Z2) has exhibited the highest compressive strength with an increase of 22% compared to the control sample. Other physical properties of the composites have been found to be in an acceptable level.Highlights Dental composites with HA and ZrO2 fillers were developed by a mortar mill. Synergistic effect of HA and ZrO2 nanoparticles was investigated. Mechanical properties of dental composites were significantly improved. Physical properties of dental composites were found to be at acceptable levels. Depth of cure decreases with increasing HA and ZrO2 loading. Synthesis of a resin-based dental composites containing HA and ZrO2 nanoparticles by a mortar mill and characterization of microstructural and mechanical properties. imageArticle Fatigue-Resistant Design of Carbon/Epoxy Composites Based on a Failure Tensor Polynomial Model by Particle Swarm Optimization-Sequential Quadratic Programming Algorithm(Sage Publications Ltd, 2024) Deveci, Hamza Arda; Artem, Hatice Secil; Guenes, Mehmet Deniz; Tanoglu, MetinThis article introduces a design procedure to find the optimum fiber orientations of carbon/epoxy composite laminates for fatigue life advancement. The approach incorporates a fatigue failure tensor polynomial model and employs a hybrid algorithm, combining particle swarm optimization and sequential quadratic programming. Firstly, material properties of quasi-static and fatigue of the carbon/epoxy composites, fabricated by the vacuum-assisted resin transfer molding method, were determined to be used in the model. Various design problems involving two optimization scenarios were then solved using the hybrid algorithm. The algorithm's performance was also evaluated by specific test problems, confirming its speed and robustness. The optimally fiber-oriented carbon/epoxy composite laminates having maximum fatigue lives were obtained for many critical in-plane cyclic loading cases. To validate the proposed design procedure, two optimum designs were experimentally verified under uniaxial loading conditions. The results indicated a good correlation between the estimated fatigue life of the optimally designed laminates and experimental data. This methodology offers a promising approach for the design of carbon/epoxy composite laminates with superior fatigue strength, particularly significant in specific industrial applications.
