Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ2Comparative 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.
- MakaleAçık Erişim2026Scopus SJRQ2Low-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.
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İncele - MakaleYalnız künye2026Scopus SJRQ2Identifying 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.
- MakaleAçık Erişim2023Farklı 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.
- MakaleAçık Erişim2023Scopus SJRQ2Experimental 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.
AtıfScopus7WoS7OpenAlex7İncele - MakaleAçık Erişim2023Scopus SJRQ3Numerical 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.
AtıfScopus1OpenAlex2İncele - MakaleAçık Erişim2022Scopus SJRQ2Investigations 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.
AtıfScopus9WoS9OpenAlex10İncele - MakaleYalnız künye2021Determination 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.
- MakaleAçık Erişim2021Scopus SJRQ2An 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.
AtıfScopus12WoS13OpenAlex14İncele - MakaleYayıncıda açık erişim2021Scopus SJRQ2Determination 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.
AtıfScopus8WoS6OpenAlex8İncele - MakaleAçık Erişim2020Scopus SJRQ3Effect of loading rate on cohesive parameters of the adhesive Araldite 2015
Erbayrak, Engin; Ozer, Halil
This study addresses the effect of loading rates on cohesive parameters and microstructural composition of the Araldite 2015 adhesive. Double Cantilever Beam (DCB) samples were tested under the loading rates of 1, 5, 10, 20, 100 and 200 mm x min(-1). The Park-Paulinho-Roeser model (PPR model) was used to get cohesive parameters. In modelling of the softening behavior, inverse analyses were performed using the date obtained from the PPR softening curves. It was seen that the fracture energy and cohesive parameters are decreasing with increasing the loading rate. However, there seems to be a transition region where the fracture energy nearly remains constant. Microstructural analyses were implemented in order to study the effects of the loading rates on the characteristics of the fracture surfaces. It was concluded that the loading rates greatly influence the distribution of micro-voids in the epoxy matrix. Moreover, the presence of voids in epoxy matrix improved the plastic deformation around the crack tip and increased the fracture toughness.
AtıfWoS3İncele - MakaleAçık Erişim2020Scopus SJRQ2Investigations of Strain Rate Effects on the Mechanical Properties of Hybrid Composite Laminate Under Varying Temperatures
Erbayrak, Engin; Gumus, Beril Eker; Yuncuoglu, Ercument Ugur; Kahraman, Yusuf
The mechanical behavior of hybrid composite laminates under varying strain rates and temperatures was investigated in this study. The hybrid composite laminate is constituted as a sequential stacking sequence of plain-woven carbon-fiber-reinforced epoxy (CFRE) and plain-woven glass-fiber-reinforced epoxy (GFRE) laminates. Vacuum-assisted resin transfer molding (VARTM) process was used to fabricate the composite laminates. Hybrid composite laminates (HCGFRE) were tested under four different strain rates (0.05 min−1, 0.5 min−1, 2.5 min−1, 5 min−1) and three different temperatures (RT, 60 °C, 100 °C). Microstructure analysis was performed to observe the voids, fiber delamination and matrix failure occurring in the composite laminate. In numerical analyses, continuum damage mechanics material model (MAT 58) was utilized in LS-DYNA® explicit finite element program to simulate the mechanical properties of CFRE, GFRE and HCGFRE laminates. It was determined that the tensile strength of all composite laminates is increasing by increasing the strain rates in all temperatures. The continuous damage mechanics material model (MAT 58) was found to be suitable for simulating woven composite laminate under different strain rates and temperatures. In microstructural study, it was not observed significant changes in the microstructure of composite laminates by changing strain rates.
AtıfScopus1WoS1OpenAlex3İncele - MakaleAçık Erişim2020Scopus SJRQ3Determination of the impact damage threshold point of composite material using fuzzy-base taguchi method
Erbayrak, Seda; Erbayrak, Engin
In this study, the impact damage threshold point of composite materials was determined using the optimum design parameters obtained from the Fuzzy Based Taguchi Method (FBTM). It is known that both Taguchi and Fuzzy methods provide optimization of design parameters yet, in Taguchi method, optimization of design parameters is not sufficient in solving multi response optimization problem. Therefore, Fuzzy Logic system was combined with the Taguchi system for working out the multi-response optimization problem. In this study, the low velocity impact damage analyses were performed in an LS-DYNA 3D explicit finite element program. ASTM D7136/D7136M standard was used during the low velocity impact analyses. In explicit finite element analyses, contact algorithms were executed to observe better damage zone shapes. Furthermore, the control parameters (termination and computation time step) were tuned to provide perfect correlation with the force-energy-time histories. The study concluded that Fuzzy Based Taguchi Method (FBTM) is much more capable of optimizing the design parameters that predict the impact damage threshold point of the composite material.
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