Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dogan, Akar(5)
- Aslan, Alper(3)
- Akkurt, Nevzat(2)
- Mahmat, Aybars(2)
- Özyurt, Özcan(2)
- Abbas, Ashraf A(1)
- Aksakal, B.(1)
- Aksoy, M.E.(1)
- Akti Aslan, Seda(1)
- Arikan, Volkan(1)
- Arman, Yusuf(1)
- Aslan, N.(1)
- Aydoğdu, Burcu(1)
- Aydoğmuş, Ercan(1)
- Aytar, Mehmet(1)
- Ayçin, Ejder(1)
- Açar, Mikail(1)
- Ağar, Salih(1)
- Canbay, Canan Aksu(1)
- Chen, Lufang(1)
- Demirel, Maruf Hurşit(1)
- Deniz, Şermin(1)
- Denizalp, Nuran Varlı(1)
- Dikici, Burak(1)
- Djele, Akim(1)
- Dogan, Gurkan(1)
- Doğan, Akar(1)
- Erden, Yavuz(1)
- Erecevit Sönmez, Pınar(1)
- Ergen, Burhan(1)
- Guler, Omer(1)
- Guler, Serkan(1)
- Göcxmen, Elifcan(1)
- Gülçiçek, Demet(1)
- Harun, Zambri(1)
- Karaduman, Oktay(1)
- Karakuzu, Ramazan(1)
- Kaya, Sema Kayapinar(1)
- Kayapinar Kaya, Sema(1)
- Khor, Yu King(1)
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ1Exploring research themes in the Journal of Librarianship and Information Science: Insights from topic modelings
Aslan, Alper; Özyurt, Özcan
This study aims to explore research interests and trends in the journal by analyzing the entire publication history of the Journal of Library and Information Science (JoLIS) between 1969 and 2023 using Latent Dirichlet Allocation (LDA). A comprehensive topic modeling analysis was conducted on 1437 articles for which titles, abstracts and keywords were available. The research focuses on identifying key thematic shifts in the journal’s publications. The findings highlight that topics such as Information Literacy & Research and Librarian Roles & Skills are growing in importance, while traditional topics such as Cataloging & Classification are declining. The results reveal shifts in the focus of the LIS field, providing critical insights to guide future research. In particular, Information Literacy & Research emerges as a highly accelerating topic, reflecting the need for digital competencies in response to evolving information environments. Meanwhile, declining interest in Cataloging & Classification is in line with the automation of traditional library functions, shifting training priorities toward digital literacy and data management skills. By mapping the evolution of research priorities, this study serves as a valuable resource for LIS researchers and practitioners, helping them to align their work with future developments in the field.
AtıfScopus9WoS7OpenAlex11
İncele - MakaleYalnız künye2026Scopus SJRQ2Influence of infill design on mechanical behavior of PLA-TPU hybrid sandwich beams
Arikan, Volkan; Dogan, Akar; Guler, Serkan
The purpose of this work is to analyze the mechanical behavior of hybrid sandwich beams that were printed using the Fused Deposition Modelling (FDM) technology. These beams were made of Polylactic Acid (PLA) and Thermoplastic Polyurethane (TPU) materials. Standard mechanical tests (ASTM C393 and C365) were utilized in order to assess the impact that several infill patterns (Cubic, Octet, and Trihexagonal) and infill densities (ranging from 15% to 40%) had on the flexural and compression performance of the material. According to the findings, trihexagonal patterns demonstrated improved energy absorption capabilities when subjected to compression, but octet designs offered superior flexural stiffness, particularly in hybrid constructions. According to the findings of tests conducted with hybrid constructions consisting of a TPU core and a PLA surface layer, the effect of infill patterns on component strength is directly influenced by the change in the material character, and it is possible that various materials would exhibit different manifestations of this effect. These findings offer useful information that may be used to optimize lattice geometry and hybridization procedures for the purpose of developing high-performance lightweight structures for engineering applications.
AtıfWoS1OpenAlex2İncele - MakaleAçık Erişim2026Scopus SJRQ2Sustainable epoxy based biocomposites reinforced with Melilotus officinalis: Structural, mechanical, thermal, and dielectric performance evaluation
Solmaz, Adnan; Açar, Mikail; Demirel, Maruf Hurşit; Deniz, Şermin; Aydoğmuş, Ercan
The aim of this study is to investigate the manufacturability of Melilotus officinalis (L.) reinforced epoxy biocomposites as a renewable biofiller and to characterize the mechanical, thermal, and dielectric properties of these materials. For this purpose, composites containing biomass at 0, 3, 6, and 9 wt.% were prepared; the samples were examined by tensile testing, FTIR, SEM, EDX, XRD, Shore D hardness, thermal conductivity, and dielectric analysis. The findings showed that with increasing M. officinalis content, tensile strength, hardness, and density decreased, while ductility and elongation at break improved. The significant decrease in thermal conductivity revealed an increase in heat insulation efficiency. Dielectric analyses showed that strong interfacial polarization occurred at low frequencies, and the dielectric constant and loss values decreased as the frequency increased. SEM examinations confirmed that the plant-derived filler was homogeneously distributed and formed acceptable interfacial adhesion with the matrix. In conclusion, although the use of synthetic epoxy matrix and the decrease in mechanical strength limit load-bearing structural applications, M. officinalis is a promising biofiller for lightweight and partially bio-based epoxy composites thanks to its increased ductility and improved thermal insulation properties. © The Author(s) 2026. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
- MakaleAçık Erişim2025Scopus SJRQ1Unveiling 50 years of librarianship research: An innovative study using unsupervised AI techniques
Akti Aslan, Seda; Turgut, Yiğit Emrah; Aslan, Alper; Özyurt, Özcan
In this study, 3646 articles published in the Scopus database between 1975 and 2024 were analyzed to examine the main research themes, trends, and research gaps in the field of librarianship. Using Latent Dirichlet Allocation (LDA) implemented in Python (Gensim, spaCy, pyLDAvis), a 17-topic model with a coherence score of 0.5266 was generated. The preprocessing steps included tokenization, lemmatization, bigram/trigram construction, and the removal of both general and domain-specific stopwords. The bibliometric analysis showed that most publications were classified under Social Sciences (93%), with the USA (1961 articles) being the leading contributor. Among the identified themes, “Information, Research, and Technology” (10.59%), “Students’ Information Literacy” (9.22%), and “Information Development” (8.23%) emerged as the most prominent, while “Professional Identity and Practice” (3.37%) and “Education and Research Competency” (3.65%) were underrepresented. Trend analyses revealed that technology-related topics have accelerated significantly since 2010, reflecting the digital transformation of librarianship. In contrast, traditional themes such as “Information Development” and “Health and Medical Services” have declined in momentum. The study shows that digitalization and information literacy remain dominant in the field. In addition, it concludes that significant research gaps exist in professional identity, education, and competency development.
AtıfScopus1WoS1İncele - MakaleAçık Erişim2025Scopus SJRQ2Modeling and analysis of WEDM with a new deep neural network
Mahmat, Aybars; Dogan, Gurkan; Ergen, Burhan; Tosun, Nihat
In some cases, the models targeted in machining processes are difficult to apply to industrial production. Artificial intelligence techniques applied to industrial production methods in recent times eliminate these problems in machining. The use of deep learning methods in solving these problems has recently increased. In this study, a new deep neural network (DNN) based on artificial neural networks is proposed to model the machining of AISI4140 steel by wire electrical discharge machining (WEDM). The proposed DNN model predicts surface roughness (SR) and wire wear ratio (WWR), which are the most important inferences in cutting with WEDM. Obtaining inferences such as SR and WWR in a real experimental environment means a lot of time and cost. With the proposed model, there is a significant reduction in time and cost factors. The dataset used to train and test the proposed model was obtained from the real experimental environment. For training and testing the model, the data set is divided into two parts: 20% test data and 80% training data. In the experimental tests carried out with the proposed model, error rates such as Mean Absolute Error (MAE), R2, and Mean Squared Error (MSE) accuracy rate between SR and WWR values estimated according to the SR and WWR values obtained from the real environment were examined. MAE, MSE, and R2 for SR reached 0.0495, 0.0005, and 98.48%, respectively, while MAE, MSE, and R2 for WWR reached 0.0156, 0.0036, and 98.39%, respectively. These results of the proposed model provided a lower error rate and higher accuracy than the state-of-the-art models in the literature.
AtıfScopus5WoS5OpenAlex7İncele - MakaleYalnız künye2025Scopus SJRQ2Experimental comparison of conventional and ultrasonic-assisted high-speed drilling of glass fiber reinforced epoxy composites
Ağar, Salih; Mahmat, Aybars; Doğan, Akar
Glass fiber reinforced epoxy composites are favored in several industries, including automotive and aerospace, owing to their superior strength-to-weight ratio. Drilling is a prevalent machining procedure employed to add fasteners for laminate assembly. Nonetheless, drilling these composites presents significant challenges due to the abrasive characteristics of the reinforcement, necessitating an examination of machining performance. During the drilling of composites, cutting temperature, thrust force, and delamination damage are primary concerns. In recent years, high-speed ultrasonic drilling, an innovative machining technique designed to address these challenges, has garnered significant interest. This investigation involved high-speed ultrasonic drilling and conventional drilling of glass fiber reinforced epoxy material. In the studies, optimal conditions were studied by evaluating thrust force, cutting temperature, and delamination damage by varying speeds, feed rates, and frequencies. The thrust force was 11 N in the traditional approach at 40,000 rpm, but it was recorded at 9 N with the ultrasonic method. Moreover, with ultrasonic drilling, cutting temperatures decreased by over 25% relative to traditional drilling, attributable to the harmonic motion that dissipates heat in the drilling zone. Analysis of the drilling region revealed a notable enhancement in damage, particularly in delamination, with the application of ultrasonic drilling. The experimental results indicate that ultrasonic machining enhances machining performance.
- MakaleAçık Erişim2024Scopus SJRQ2Effects of Ga, Nb, V, Zr, and Cr on the crystal structures and thermal behavior of CuAlMn shape memory alloys
Özkul, İskender; Karaduman, Oktay; Canbay, Canan Aksu
CuAlMn alloys are cheaper and more promising alloy types compared to NiTi alloys. In this study, based on CuAlMn shape memory alloy, thermodynamic and structural characteristics of some new alloys containing four elements were investigated in detail. In this study, five new quaternary shape memory alloys, each containing a CuAlMn base alloy and a different fourth additive element (Ga, Nb, V, Zr, and Cr), were produced. The properties of the obtained alloys were characterized using a series of analysis methods such as X-ray diffraction (XRD), optical microscopy, differential scanning calorimetry (DSC), and differential thermal analysis (DTA). The results showed the effects of different elements on the crystal structures of the alloys and how different elements could change the thermal behavior of the alloys.
AtıfScopus4WoS3OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ1The nation’s happiness, women’s altruism and the affective politics of self-blame: Generating a ‘mood of commitment’
Gülçiçek, Demet
This article contributes to the growing interest in affect and emotions in sociological research, with a specific focus on ‘mood’, developing the concept ‘mood of commitment’. It approaches political commitment as a mood, an affective lens, a dedication to a greater cause, asking how political commitments might be a low intensity affective relationship, and also a heightening, high intensity rhythm at the same time. I conceptualise ‘mood of commitment’ as an object of analysis that can be engaged to critically understand a wide range of political commitments. This article focuses on the case of Ottoman Muslim women’s movements in the early 20th century, amid the turmoil of nationalist movements and ‘modernisation’ processes. It firstly analyses objects of desires that are circulated to be persuasive in the political movements, and attunement of women’s movements with already existing nationalist movements. It secondly unpacks the kind of work involved in claiming to be in the ‘right’ mood of commitment, emphasising the production of hegemonic positions.
AtıfScopus2WoS2OpenAlex2İncele - MakaleYalnız künye2024Scopus SJRQ2Plant extract-based biosynthesis of silver nanoparticle and silver–zinc nanocomposites-doped hydroxyapatite and its antimicrobial activity
Unal, Ilkay; Aydoğdu, Burcu; Aytar, Mehmet
Hydroxyapatite (HAp) is an essential material in the biomedical field because of its chemical composition, similar to the apatites found in bones. The lack of bactericidal properties of HAp-based materials cannot prevent the adhesion and growth of bacteria. However, it can develop composite biomaterials using nanoparticles (NPs) such as silver (Ag) and zinc (Zn), which exhibit biocidal behaviours to control resistant microorganisms. This study aimed to prepareHAp–AgNPs and HAp–Ag@ZnNPs nanocomposite and evaluate their antimicrobial properties against Gram-positive and Gram-negative bacteria. HAp powders were produced from sheep bone. An aqueous extract of Marrubium astracanicum was used as a reducing and stabilising agent for the synthesis of NPs. The composites were characterized by XRD, SEM–EDX, SEM and FTIR. In vitro biocompatibility assessment was determined by agar well diffusion tests. The HAp–Ag@ZnNPs nanocomposites showed stronger antimicrobial activity than HAp–AgNPs against bacteria and fungi, while pure HAp did not show any effect.
AtıfScopus6WoS5OpenAlex4İncele - MakaleYalnız künye2024Scopus SJRQ2Urban heat island patterns in garden cities: Putrajaya as a case study
Harun, Zambri; Akkurt, Nevzat; Khor, Yu King; Abbas, Ashraf A; Lotfy, Eslam Reda
The garden-city model, characterised by sprawling urban expansion and extensive open spaces, features green and water surfaces alongside substantial road networks, large parking lots and unshaded lands. This diverse landscape contributes to uneven air temperature distribution within the city. Our study investigated urban heat island (UHI) patterns in various urban environments within Putrajaya, focusing on rural, business, residential and near-water areas. Atmospheric data were collected over a year. Putrajaya exhibits two distinct UHI patterns: cool-day-hot-night in residential zones and hot-noon-temperate-elsewhere in impermeable areas. Business areas display alternating patterns based on seasonal climatic conditions and anthropogenic factors. The efficacy of artificial water bodies as a UHI countermeasure in garden cities depends on the size of the water body and the nature of the surrounding land cover. Shaded and green areas exhibit UHI intensities limited to 3°C, while impermeable areas, regardless of proximity to water surfaces, experience UHI up to 6°C. Overall, the garden-city model tends to restrict UHI variations within −1 to 3°C compared to −2 to 4°C in nearby Kuala Lumpur.
AtıfScopus9OpenAlex7İncele - MakaleYalnız künye2023Scopus SJRQ2New Deep Learning-Based Passenger Flow Prediction Model
Utku, Anıl; Kaya, Sema Kayapinar
The ability to predict passenger flow in transport networks is an important aspect of public transport management. It helps improve transport services, aids those responsible for management to obtain early warning signals of emergencies and unusual circumstances and, in general, makes cities smarter and safer. This paper develops a long short-term memory-based (LTSM-based) deep learning model to predict short-term transit passenger volume on transport routes in Istanbul. This prediction model has been created using a dataset that included the number of people who used different transit routes in Istanbul at one-hour intervals between January and December 2020. The proposed multilayer LSTM-based deep learning model has been compared with popular models such as random forest (RF), support vector machines, autoregressive integrated moving average, multilayer perceptron, and convolutional neural network. The experimental findings showed that the proposed multilayer LSTM-based deep learning model outperformed the other models with regard to prediction for each transfer route. Furthermore, RF, one of the machine learning models used, produced remarkably successful results.
AtıfScopus19WoS12OpenAlex16İncele - MakaleAçık Erişim2022Scopus SJRQ1Academicians’ awareness, attitude, and use of open access during the COVID-19 pandemic
Turgut, Yigit Emrah; Aslan, Alper; Denizalp, Nuran Varlı
The aim of this research is to reveal academics’ awareness, attitude, and use of open access. In line with the research purpose, the survey research design is adopted. This research consists 151 academics from 12 basic research areas; eight of them being Professor Dr, 17 being Associate Professor Dr, 49 being Doctor Lecturer, and 77 being Research Assistant or Lecturer. A questionnaire consisting of 19 open access and five demographic information questions was used for the data collection tool. The research results show that 75% of the academics have open access awareness and that their awareness is generally created by information that they obtain through the Internet and their friends. In addition, most of the academics indicate that their awareness of open access has increased during the pandemic period. When considering the level of academics’ use of open access, it is found that 75% of the academics use articles in open access journals for their own research and 51% of the academics do not publish any articles in open access journals.
AtıfScopus20WoS18OpenAlex19
İncele - MakaleYalnız künye2022Scopus SJRQ3Boron-incorporated biocomposite coatings on 316L and NiTi alloys: Enhanced structural, antibacterial activity, and cell viability performances
Aslan, N.; Aksakal, B.; Aksoy, M.E.
Boron doped (5 %, 10%, and 15 wt.%) Hydroxyapatite (B-HA) biocomposites were syntesized and coated on 316L SS and NiTi (Ni-45Ti) metallic substrates by using the electrophoretic deposition process (EPD). The morphological and structural characterization of the coatings was executed using scanning electron microscopy (SEM) and X-ray diffraction devices (XRD). Antibacterial tests were conducted using Escherichia coli (E. coli, JM103) and Staphylococcus aureus (S. aureus, ATCC29293) microorganisms. The mitochondrial activity assay (MTT)-[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] was used to examine cell viability and cytotoxicity in Saos-2 osteoblast cells. HA and boron peaks, as well as B-TCP and metallic components, were detected in XRD examinations. Porous morphologies were generated on the surface with boron doped B-HA coatings, as revealed by SEM views. Antibacterial activity studies revealed that both metallic coating groups, notably with boron doping, demonstrated antibacterial activity against gram-negative E. coli and gram-positive S. aureus. The antibacterial activity of the 316L group was shown to be better than that of the NiTi group in comparisonal testing. The syntesized boron-doped biocomposite coatings did not have any detrimental effects on living cells, according to cell viability studies. The cell viability rate was found to be greater in NiTi coatings than in 316 SS coatings, and the impact was amplified by the addition of boron.
AtıfScopus6WoS4OpenAlex7İncele - MakaleYalnız künye2022Scopus SJRQ2Single and repeated low-velocity impact response of E-glass fiber-reinforced epoxy and polypropylene composites for different impactor shapes
Dogan, Akar
This study focuses on the effects of low-velocity impact (LVI) response of thermoset (TS) and thermoplastic (TP) matrix-based composites. In this study, the effects of the impactor shapes on the low-velocity impact response of the composite panels that produced from different matrix was investigated. Unidirectional E-glass fiber fabrics with an areal density of 300 g/m2 as reinforcement and epoxy matrix were used to produce TS composite. The vacuum-assisted resin infusion molding (VARIM) method was used to manufacture composite panels. The thermoplastic composites were manufactured with E-glass fiber-reinforced polypropylene prepregs. The tensile strength of TS matrix-based composites is higher than TP matrix-based composites that have the same fiber volume fraction. Despite being under the same impact energy, the TP specimens possess higher perforation threshold than TS specimens. The shape of the impactor significantly affected the perforation threshold. Besides, the impact number that caused perforation reduced dramatically in conical impactor. The repeated impact number that caused perforation is 36 for hemispherical (HS) impactor, but it is only 3 for conical impactor for polypropylene matrix-based composite. Moreover, a significant effect of fiber volumetric ratio on impact resistance was observed. The perforation threshold of glass fiber-reinforced polypropylene composites for 40% and 50% fiber volume fraction are 61 and 98 J, respectively. The perforation threshold of TP and TS specimens for HS impactor that has the same stacking sequence is 61 and 55 J, respectively.
AtıfScopus42WoS45OpenAlex44İncele - MakaleYalnız künye2021Scopus SJRQ2High temperature effect on quasi-static and low velocity impact behaviors of advanced composite materials
Karakuzu, Ramazan; Djele, Akim; Dogan, Akar
In this study, the effect of ambient temperatures on the punch shear and low-velocity impact behavior of S2 glass fabric and carbon-kevlar hybrid fabric reinforced epoxy composites was investigated. The quasi-static tests (QST) were performed by using a Universal Shimadzu Tensile Testing Machine with various crosshead speeds. Low-velocity impact (LVI) tests were also carried out by using the CEAST Fractovis Plus impact test machine at different impact energies. Flat-nose impactors with a cylindrical punch diameter of 12.70 mm were mounted to the test machines. Both tests have been carried out at various temperatures. After the experiments, the load-displacement, the absorbed energy-impact energy/crosshead speed and punch shear strength graphs are plotted. From the obtained results it can be said that, in penetration cases of low-velocity impact and quasi-static tests, absorbed energy and punch shear strength values show similar behavior for hybrid carbon-kevlar/epoxy at each temperature except for 80 °C while these values are different from each other for S2 glass/epoxy at all temperatures.
AtıfScopus16WoS14OpenAlex14İncele - MakaleAçık Erişim2021Scopus SJRQ2Towards the circular economy: Analysis of barriers to implementation of Turkey’s zero waste management using the fuzzy DEMATEL method
Ayçin, Ejder; Kayapinar Kaya, Sema
Zero waste has an important position in the circular economy model in terms of manufacturing recyclable products instead of products to be consumed quickly, reducing the amount of waste, developing and implementing recycling/reuse technologies, and thus ensuring resource efficiency. A zero-waste strategy is one of the basic steps to achieve the goal of the circular economy. The number of studies conducted on Turkey’s zero waste management strategies referring to the circular economy is quite limited. To fill this gap in the literature, this study aims to identify the potential barriers which have an important role in zero waste management practices in Turkey. Through a broad literature review and expert opinions, 12 key barriers for zero waste implementation in Turkey have been defined in view of circular economy principles. Then, fuzzy DEMATEL methodology is employed to examine which is the most influential barrier affecting zero waste management success and to identify the interdependence of these barriers. The results indicate that uncertainty of the goals and tactics relevant to the circular economy and lack of financial and economic aid are key causal barriers that affect Turkey’s zero waste management.
AtıfScopus65WoS49OpenAlex85İncele - MakaleYalnız künye2021Scopus SJRQ2Effect of roof and ceiling configuration on energy performance of a metamaterial-based cool roof for low-rise office building in China
Tang, Saihong; Akkurt, Nevzat; Zhang, Kai; Chen, Lufang; Ma, Mingquan
Cool roofs with higher solar reflectance and emittance can effectively reduce building energy consumption. However, it is still limited to use at night on account of the development of roof materials during the past decades. The newly proposed metamaterial-based cool roof (MCR) greatly improves the possibility of the radiative cooling in the daytime. To study the influence of MCR on the energy consumption for the office building, a small single-floor office was adopted to analyse the cooling performance of MCR by using EnergyPlus. In this study, the optimization analysis was conducted based on the proposed dimensionless thermal resistance (θRTR) and roof pitch (Δ). Then the annual electricity saving potential of the office building with MCR was evaluated in details based on the selected cities from all five climate zones in China. The results show that more annual electricity saving can be achieved under the optimized values of θR7 = 1.53 and Δ = 20°. Furthermore, more than 15.7% of annual cooling electricity saving can be achieved while the optimized θRTR and Δ are applied.
AtıfScopus13WoS12OpenAlex15İncele - MakaleYalnız künye2021Scopus SJRQ2Smart airport: Evaluation of performance standards and technologies for a smart logistics zone
Göcxmen, Elifcan
Owing to the current context of Industry 4.0, the importance of smart technologies in airport systems have increased substantially. State-of-art applications for transportation planning incorporating baggage services, routing, security, and safety are an evolving domain for both practitioners and researchers dealing with aviation applications. In this context, this paper seeks to answer these questions: Which standards are aimed at a smart airport to make the transportation planning sound? Which propositions are made based on the obtained prioritized standards? This study deals with standards including Environmental Effects, Docking & Navigation, Object Detection & Protection, Communications & Integration, and Terminology using a practical decision support system based on an analytical hierarchy process (AHP) and fuzzy inference system (FIS). Computational results reveal that the Object Detection & Protection standard has an effect on a safe and smart system. To give an overview of this standard for a smart logistics zone (SLZ), an architecture of autonomous robot units and a baggage handling system is proposed in this study. The suggested approach analyzes the obstacle photos obtained by cameras and allows the end-user to control the calculations visually. This research could provide advice to airport planners about smart policies and improving operations.
AtıfScopus25WoS10OpenAlex26İncele - MakaleYalnız künye2021Scopus SJRQ1Low-velocity impact, bending, and compression response of carbon fiber/epoxy-based sandwich composites with different types of core materials
Dogan, Akar
This study focuses on the investigation of the effects of different core types on the low velocity impact, three-point bending and out-of-plane compression loading performance of sandwich composites. Three core materials were selected: Balsa wood, PVC foam, and Ayous wood. The facesheets of sandwich composites were produced by woven carbon/epoxy. Balsa and PVC foam are widely used in sandwich composites as core materials. In this study, Ayous wood, which is the lightest tree after Balsa, was used as core material in addition to traditional core materials. Woven carbon fiber fabrics with an areal density 200 g/m2 as reinforcement and epoxy matrix were used to produce the sandwich composite. Vacuum-assisted resin infusion molding method was used to manufacture composite panels. A number of tests under various impact energy levels for three different sandwich composites were conducted with Fractovis Plus impact testing machine in order to investigate the energy absorption capacity of sandwich composites. Maximum contact forces, absorbed energies, and the maximum deflections of sandwich panels were obtained for each impact energy level. Despite having the same facesheets, Ayous core sandwich composites possess a higher perforation threshold than Balsa and PVC foam sandwich composites. The perforation threshold of Balsa, PVC foam, and Ayous sandwich composites are 85, 72, and 170 J, respectively. In addition, the Ayous core sandwich composites have better bending and compression strengths. The bending strength of the Ayous sandwich composite is higher about six times than PVC sandwich composite and about two times than Balsa sandwich composite.
AtıfScopus61WoS56OpenAlex56İncele - MakaleYalnız künye2020Scopus SJRQ2The effect of graphene nano-sheet (GNS) weight percentage on mechanical and corrosion properties of AZ61 and AZ91 based magnesium matrix composites
Guler, Omer; Say, Yakup; Dikici, Burak
In this study, the effect of graphene nano-sheets (GNSs) on mechanical and corrosion properties of AZ61 and AZ91 based composites was investigated, detail. GNSs have been successfully produced by the liquid phase exfoliation (LPE) method and then, added AZ61 and AZ91 matrix with 01, 0.2, and 0.5 wt% GNSs for the production of the composites. The composite compacts were produced by powder metallurgy technique and sintered for 2 h at 500 °C under Ar atmosphere. The composite characterizations were carried out by scanning and transmission electron microscopes (SEM, TEM), electron dispersive spectroscope (EDS), Raman spectroscopy, and X-ray diffraction. The mechanical properties and corrosion behaviors of the composites have been compared with compression tests and potentiodynamic scanning (PDS) techniques, respectively. The results showed that the compressive strength of the composites increased with increasing GNS amount in both the AZ61 and AZ91 matrix alloys. The most susceptible composites to corrosion for both AZ61 and AZ91 matrix were observed in the 0.5 wt% GNS containing structures. However, there is a certain ratio of GNS in the Mg matrix to achieve good corrosion resistance.
AtıfScopus29WoS25OpenAlex33İncele