Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2026Scopus SJRQ2/r/bayburt/12819
  Comparative investigation of composite-metal lap joints with mono-adhesive and thermoplastic-reinforced mixed adhesive at elevated temperatures

  Erbayrak, Engin; Eker, Beril; Colak, Murat

  This study primarily examines the strength of a single lap joint having a mixed adhesive overlap consisting of a single adhesive and its thermoplastic reinforced state under varying temperatures. In the single lap joint, Titanium-Boron reinforced A356 aluminum was employed as the metal adherend, while plain woven glass fiber-reinforced epoxy (GFRE) was employed as the composite adherend. In the application of the mixed adhesive overlap, the brittle adhesives were employed in the middle section of the lap joint, while the reinforcement of the thermoplastics was employed on the adhesives at both sides of the lap joint. The single lap joints were subjected to tensile tests at 1 mm/min loading rates under room temperature and 120 °C, which is the melting point of the copolyester. In the numerical analysis, the cohesive zone model was applied in order to define the adhesives; however, elastic isotropic and orthotropic material behaviors were employed for the metal and composite adherends, respectively. Eventually, it is determined that the strength of a mixed adhesive lap joint consisting of a single adhesive and its thermoplastic reinforced state is better than a lap joint made with the mono-adhesive alone. Although literature suggests that mixed adhesive overlaps can be formed using at least two different adhesives (one ductile and one brittle), this study demonstrated that a mixed adhesive zone can be created using a single adhesive and thermoplastic reinforcement.

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• MakaleAçık Erişim2026Scopus SJRQ2/r/bayburt/11576
  Low-velocity impact analysis of metal-composite joints with grain-refined A356 and reinforced epoxy adhesive using six node pentahedron cohesive elements

  Erbayrak, Engin; Colak, Murat; Noberi, Cansu

  This study evaluates the strength of double lap joints composed of metal composite adherends and epoxy adhesive subjected to low impact energies (20 J, 40 J). The study was carried out through experimental and numerical methods to understand the strength of lap joints comprehensively. In the production of double lap joints, A356 aluminum and grain-refined aluminum adherends were used as the metal components. To refine the grain structure, titanium (Ti) and boron (B) were added to the liquid metal at a rate of 0.01% of the total metal weight (A356-TiB). The composite laminates consisted of glass/epoxy and aramid/epoxy, made with unidirectionally oriented fibers. Araldite 2015 epoxy adhesive, available in both unreinforced and copolyester-reinforced forms, was utilized to bond the metal and composite materials. In the numerical analysis of double-lap joints, the metal and composite adherends are modeled using 8-node solid elements, while the adhesive is represented by 6-node pentahedron cohesive elements. Furthermore, a surface-to-surface, two-way treatment of contact was created between the impactor and the metal adherend. Consequently, the maximum impact loads obtained from the numerical analysis are in good agreement with the experimental results for both impact energies.

  AtıfScopus4·WoS5·OpenAlex4

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• MakaleYalnız künye2026Scopus SJRQ2/r/bayburt/11231
  Identifying the optimal flexural performance of metal-composite single-lap joints with copolyester-reinforced epoxy adhesive under various loading rates using the Grey Relation Analysis

  Erbayrak, Engin; Erbayrak, Seda; Eker, Beril; Colak, Murat

  This study examines the best flexural performance of metal composite single-lap joints fabricated with copolyester-reinforced epoxy adhesives at various loading rates using the Grey Relation Analysis (GRA). The study consists of three parts. The first part involves the formation of metal composite single-lap joints and their experimental approach under different loading rates. In the experimental approach, A356 aluminum was used as the metal material with the addition of titanium (Ti) and boron (B) additives. Plain-woven glass fiber-reinforced epoxy (GFRE) and plain-woven carbon fiber-reinforced epoxy (CFRE) were served as the composite materials. The lap joints were tested in three-point bending tests under loading rates of 1, 10, and 50 mm/min, respectively. In the second part, a numerical analysis was conducted using boundary conditions similar to the experimental conditions. In the numerical analysis, a 6-node pentahedral cohesive element was utilized, representing a novel approach for modeling adhesives in finite element analysis (FEA). When experimental and numerical results were compared, a difference of 4.36% was observed between the maximum load values and 6.80% between the failure displacements. Based on these results, it can be said that the experimental results converge with the numerical results. In the last part of the study, performance rankings of metal composite joints were determined using the Grey Relational Analysis (GRA) method, which enabled us to identify the optimum joint. This systematic approach facilitated the scientific design of joints that demonstrate optimal flexural performance under various loading conditions.

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• MakaleAçık Erişim2023/r/bayburt/16512
  Farklı Bayburt Taşı (Tüfit) Boyutlarını Taşıyan Helezonun Doğal Frekans Değişiminin Belirlenmesi

  Erbayrak, Engin; Kırar, Burhan

  Helezon milin dönme hareketi ile tozu veya çok küçük tanecikli partikülleri taşıyan mekanizmaya helezon konveyör denir. Helezon konveyörlerin çalışma prensibi silindirik bir boru içerisine yerleştirilmiş helezon milin motor gücü ile dönmesi sayesinde toz partiküllerinin taşınmasıdır. Taşıma işlemi toz taneciklerini mekanizmanın tepesindeki besleme borusundan konveyöre helezon milinin kanatlarına (heliks) aktarılması ile olmaktadır. Bu çalışmada vidalı konveyörün ölçekli bir prototipi üretilmiştir. Prototip kullanılarak farklı boyutlardaki Bayburt taşı (Tüfit) taşınmış ve taşıma sırasındaki doğal frekans değişimleri ölçülmüştür. Bayburt taşının ince partiküllerin de doğal frekans değeri en düşük belirlenirken (15.67 Hz), kaba partiküllerde ise doğal frekans değeri yüksek belirlenmektedir (20.32 Hz). Bu durum zorlanmış titreşimin bir örneği olan bu ölçüm için beklenen bir durumdur. Hacimsel boyutu artan partiküllerin ağırlıklarının da artmasıyla beraber meydana getirdikleri dış kuvvet değerleri de artmaktadır. Kütle değerindeki artış ve dinamik yüklerdeki değişim doğal frekans değerini artırmıştır. Partikül boyutlarının inceden kalına doğru artmasıyla beraber doğal frekans değerleri de yüzde 10-15 aralığında arttığı gözlemlenmiştir. Sonuç olarak, konveyörde taşınan parçacıkların boyutlarının sistemin doğal frekans değerini belirlemede önemi olduğu belirlenmiştir.

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  İncele
• MakaleAçık Erişim2023Scopus SJRQ2/r/bayburt/11803
  Experimental study of adhesively bonded joints with dissimilar composite laminates under different loading rates and ambient temperatures

  Erbayrak, Engin; Gumus, Beril Eker; Yuncuoglu, Ercument Ugur

  An experimental study of the single-lap joints at different loading rates and ambient temperatures was investigated. In the experiment, a single lap joint was formed using plain woven glass fiber reinforced epoxy (GFRE) laminates, plain woven aramid fiber reinforced laminates (AFRE), and Araldite 138 M / HV998 epoxy adhesive. The composite laminates were produced using Vacuum-Assisted Resin Transfer Molding (VARTM) process. Adhesively bonded joints were created using similar and dissimilar adherends. Experiments were carried out under different loading rates (1 mm/min, 10 mm/min, 50 mm/min, 100 mm/min) and ambient temperatures (23°C,60°C,100°C). Stress–strain graphs were obtained for each experimental condition. It is seen that the maximum stress values increase as the loading rate increases in all single lap joints at all different temperatures. However, in all single lap joints, at all different loading rates, the maximum stress value decreases as the ambient temperature increases.

  AtıfScopus7·WoS7·OpenAlex7

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• MakaleAçık Erişim2023Scopus SJRQ3/r/bayburt/11673
  Numerical investigation of the Mode I/Mode II fracture behavior of the hybrid composite joints with a hybrid bondline

  Erbayrak, Engin

  In this study, the fracture behavior of fracture characterization bonded joints consisting of hybrid composite adherends and hybrid bondlines under Mode I and Mode II loadings were investigated numerically. Numerical analysis was performed using LS-DYNA. Hybrid composite laminates (HCGFRE) obtained by sequencing plain woven glass fiber reinforced epoxy (GFRE) and plain woven carbon fiber reinforced laminates (CFRE) as adherends. Araldite AV138M and Araldite 2015 epoxy adhesives were also used to create the hybrid bondline. Mode I and mode II fracture behaviors were determined by numerical modeling of the Double Cantilever Beam (DCB) and End Notched Flexural (ENF) tests, respectively. In the numerical model, firstly, the fracture parameters of the relevant adhesives were found in the literature, and verification was made utilizing the numerical model. Then, the fracture behavior in both two modes was examined by forming a hybrid bondline. In the literature, there are restricted studies examining the fracture behavior of fracture characterization bonded joints with hybrid bondlines. Additionally, it is not encountered any study determining the both mode I and mode II fracture behavior of composite fracture characterization bonded joints with hybrid bondlines. Therefore, it is thought that this study will gain significant novelties to the existing literature.

  AtıfScopus1·OpenAlex2

  İncele
• MakaleAçık Erişim2022Scopus SJRQ2/r/bayburt/13568
  Investigations of low-velocity impact behaviour of single-lap joints having dissimilar hybrid composite adherends through cohesive zone model approach

  Erbayrak, Engin

  The low-velocity impact behavior of single-lap joints was investigated in this study. In single-lap joints, woven carbon fiber reinforced epoxy (CFRE) and plain woven glass fiber reinforced epoxy (GFRE) laminates as well as a hybrid composite laminate (HCGFRE), which is formed by stacking carbon and glass composite laminates, are used as adherends. Araldite 2011 and Araldite 138 M/HV998 epoxy adhesives were used with different mechanical properties for joining similar and dissimilar composite adherends. Low-velocity impact tests were carried out with 40 J impact energy. Reaction force-time and impact energy-time graphs were obtained from the experimental study as impact response. In numerical analyses, the damage approach of composite adherend was modeled using composite stress-based failure model (Mat 59) and adhesives were modeled utilizing a mixed-mode cohesive zone model (Mat 138) that existed in LS-DYNA explicit finite element software. It was seen that the numerical results indicated a similar tendency with the experimental results due to the modeling of the adhesives using the proper cohesive zone model, the application of correct boundary conditions, and the selection of the correct contact type.

  AtıfScopus9·WoS9·OpenAlex10

  İncele
• MakaleYalnız künye2021/r/bayburt/16765
  Determination of Mechanical Properties of Single Lap Joints Having Sandwich Composite and Metal Adherend by Experimental and Numerical Approach

  Erbayrak, Engin

  In this study, the mechanical properties of single lap joints having different adherends were determined by\rexperimental and numerical approaches. Steel, aluminum, and aluminum sandwich composite material were\rused as adherend, and Araldite 2015 epoxy adhesive was used as adhesive in single lap joints. Alongside\rthe single lap joints obtained by using similar adherends, different adherends were also examined within\rthe scope of this study. In the experimental approach, tensile tests were carried out at a rate of 1 mm/min.\rAt the end of the experimental approach, the stress-strain plots of each single lap joint were determined. In\raddition, the characterization of the polyethylene polymer, which is also included in the aluminum sandwich\rcomposite material used as the adherend , was made in experimental approach by XRD test. In the numerical\rapproach, the single lap joint geometry used in the experimental approach was created in the Ansys finite\relement program. A non-linear contact was established between the adhesive and the adherend, and boundary\rconditions were applied that meet the experimental conditions. It was observed that the numerical results\rshow a similar tendency with the experimental results due to the non-linear modeling of the lap joints, the\rapplication of the correct boundary conditions, and the selection of the correct contact type.

  İncele
• MakaleAçık Erişim2021Scopus SJRQ2/r/bayburt/13554
  An Experimental and Numerical Determination on Low-Velocity Impact Response of Hybrid Composite Laminate

  Erbayrak, Engin; Yuncuoglu, Ercument Ugur; Kahraman, Yusuf; Gumus, Beril Eker

  In this study, experimental and numerical investigations were carried out in order to determine the mechanical properties and impact response of hybrid composite laminate. The hybrid composite laminate was formed from plain woven carbon fiber reinforced epoxy (CFRE) and plain woven glass fiber reinforced epoxy (GFRE) fiber using VARTM (vacuum-assisted resin transfer molding) process. The mechanical properties of the hybrid composites were determined using tensile test device with a 1 mm/min loading rate at room temperature. In addition, hybrid composites were subjected to low-velocity impact test under different impact energy levels (10, 20, 30, 40 J) for determining the impact response. Moreover, mechanical properties and impact responses of CFRE and GFRE laminates were also determined to compare to those of hybrid composite (HCGFRE). Microstructure analysis was performed to investigate the damage surfaces of the fiber and matrix in the composite material subjected to impact and tensile forces. In numerical analyses, composite damage model (Mat 54) was utilized in LS-DYNA® explicit finite element program to simulate the impact behavior of CFRE, GFRE and HCGFRE laminates. Consequently, the tensile test results showed that hybrid composite laminate behaved more ductile than carbon composite laminate and it exhibited more brittle behavior than glass composite laminate. Also, it was determined that absorbed energy and impact load capacity of HCGFRE composite laminate are between absorbed energy and impact load capacity of CFRE and GFRE composite laminate. It was determined that numerical results indicate a similar tendency with the experimental results.

  AtıfScopus12·WoS13·OpenAlex14

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• MakaleYayıncıda açık erişim2021Scopus SJRQ2/r/bayburt/13340
  Determination of flexural properties of hybrid composite using Cowper-Symonds rate-dependent material model

  Erbayrak, Engin

  This study addressed to determine the flexural properties of hybrid composite laminates (HCAFRE) under the strain rate sensitivity. The hybrid composite laminate was formed as consecutive stacking of a sequence of plain woven carbon fiber reinforced epoxy (CFRE) and a plain-woven aramid fiber reinforced epoxy (AFRE) laminates. The flexural tests were carried out at four different strain rates (0.01, 0.11, 0.55, 1.1 s−1) to determine the strain rate sensitivity of the HCAFRE. Moreover, the strain rate sensitivity of CFRE and AFRE was also determined individually. The effect of different fiber orientations (0°, 45°, and 90°) on the flexural properties of the composite laminates were also investigated at the scope of this study. In numerical analysis, composite laminates (CFRE, AFRE, and HCAFRE) were constituted in LS-DYNA finite element program using the Cowper-Symonds material model (MAT 112) which includes strain rate dependency. Consequently, it was seen that the experimental and numerical results were indicated a similar tendency to each other. Therefore, it was understood that the Cowper-Symonds material model is suited for the flexural behavior model of composite laminates under different strain rates.

  AtıfScopus8·WoS6·OpenAlex8

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