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Öğe Transverse impact and axial compression behaviors of glass/epoxy pipes subjected to seawater and impact loading(SAGE, 2013-07) Deniz, Mehmet Emin; Karakuzu, Ramazan; İçten, Bülent MuratThis article investigates the effects of seawater and impact loading on the impact behavior and compressive strength of impacted glass/epoxy composite pipes. The specimens were immersed into artificial seawater at laboratory conditions for 3, 6, 9, and 12 months. First, the impact tests were carried out on composite pipes at room temperature, and then, the axial compression tests were performed. The results of immersed samples were compared with that of reference specimens (dry). Seawater effect on the force-deflection behavior and failure mechanism is more than impact energy with increase in pipe diameter, while impact energy effect is more dominant than seawater effect for small diameters of the pipe. Compressive strength generally reduces with increase in seawater immersion time and specimen diameter except for the highest diameter.Öğe Determination of fatigue life of the unidirectional GFRP/Al hybrid composite laminates(Elsevier, 2019-06) Deniz, Mehmet Emin; Aydın, FıratThis paper investigates the effects of loading rate and fiber orientation on the fatigue behavior of the unidirectional glass-fiber reinforced-plastic/aluminum (GFRP/Al) hybrid laminated (GLARE-2) plates. Fatigue tests were performed at three kinds of stress ratios (R = 0.3, 0.1, and −0.1) on specimens with different fiber orientations, θ = 0° 15° 30° 45° 60° 75° and 90° in the GFRP layers. All the fatigue results to be presented in this article were obtained in repeated tension-tension and tension-compression at stress ratios of 0.3, 0.1, and −0.1, and the results were compared with each other. It has been shown that the specimens have the highest fatigue life in the fiber orientation direction at R = 0.3 loading rate. Also, it has been shown that the fatigue life of the specimens decreases as the loading rate decreases.Öğe Environmental effect on fatigue life of glass–epoxy composite pipes subjected to impact loading(Elsevier, 2013-01) Deniz, Mehmet Emin; Karakuzu, Ramazan; Özen, Mustafa; Özdemir, Okan; İçten, Bülent MuratThe main objective of this experimental study was to investigate the effects of seawater and impact loading on the fatigue life of glass–epoxy composite pipes under cyclic internal pressure. The pipes were produced by filament winding technique. Composite specimens were immersed in seawater for periods of 3, 6, and 9 months. After the impact tests are carried out at three different energy levels (5, 7.5, and 10 J), fatigue tests were conducted on the specimens. It is seen from results that fatigue life changes according to both impact energy and seawater immersion time. Fatigue life of non-impacted specimen is greater than the impacted one. Fatigue life increases in the impacted specimens up to 3 months and reaches generally maximum value. After that it decreases with increase in seawater immersion time. During the fatigue tests, fatigue damage types named perspiration, leakage, and eruption were observed.Öğe Effect of seawater on pin-loaded laminated composites(De Gruyter, 2018-01) Deniz, Mehmet Emin; Karakuzu, Ramazan; Kanlıoğlu, HalitThe aim of this study was to investigate the effect of seawater on bearing strength of glass-epoxy laminated composites. The ratio of the edge distance to pin diameter (E/D) was changed from 1 to 5 and that of the specimen width to pin diameter (W/D) was selected as 3 and 4 for this study. The hole of the specimen was subjected to a traction force induced by a pin. Laminated composite plates were manufactured at the Company Izoreel Composites. Tension tests were performed on pinned joint specimens with a stacking sequence of [0/90]3S. The specimens were immersed in seawater of the Aegean Sea having a salinity of about 3.5 wt.-% in a glass aquarium at laboratory for 1, 3, 6, 9 and 12 months. For each period of immersion time, failure modes and maximum failure loads of the specimens were found experimentally. The maximum reduction of the bearing strength was obtained as 38% for E/D = 3 and W/D = 3 due to the seawater effect.Öğe Determination of fatigue life of the unidirectional GFRP/Al hybridcomposite laminates(Elsevier, 2019-06-01) Deniz, Mehmet Emin; Aydin, FıratThis paper investigates the effects of loading rate andfiber orientation on the fatigue behavior of the uni-directional glass-fiber reinforced-plastic/aluminum (GFRP/Al) hybrid laminated (GLARE-2) plates. Fatigue testswere performed at three kinds of stress ratios (R = 0.3, 0.1, and−0.1) on specimens with differentfiber or-ientations,θ= 0°, 15°, 30°, 45°, 60°, 75°, and 90°, in the GFRP layers. All the fatigue results to be presented inthis article were obtained in repeated tension-tension and tension-compression at stress ratios of 0.3, 0.1, and−0.1, and the results were compared with each other. It has been shown that the specimens have the highestfatigue life in thefiber orientation direction at R = 0.3 loading rate. Also, it has been shown that the fatigue lifeof the specimens decreases as the loading rate decreases.Öğe The effect of hole diameter and loading level on fatigue behavior of glass/epoxy composite plates under 3 point bending load(Ege Üniversitesi, 2015) Deniz, Mehmet Emin; Ekinci, LokmanÖğe Effects of specimen dimensions and impact energy on energy absorption and damage of glass/epoxy composite plates(De Gruyter, 2019-02-21) Deniz, Mehmet Emin; Karakuzu, Ramazan; Algan, BerkIn this study, the impact response of laminated composite plates of various specimen dimensions under various impact energies has been investigated, experimentally and numerically. Glass/epoxy composites with [02/902/02/902]s orientations were manufactured by the hand lay-up technique. Low velocity impact tests were conducted using a CEAST-Fractovis Plus impact test machine for specimens with net impact areas; SQR76 (square with 76 mm edge), SQR150 (square with 150 mm edge) and CIR76 (circle with diameter of 76 mm). Numerical analysis was also carried out via 3DIMPACT transient finite element code including matrix cracking and impact-induced delamination criteria. Absorbed energy and the damage size of specimens were investigated for various impact energies. Delamination areas obtained by finite element were in good agreement with those experimentally obtained up to 50 J of impact energy.Öğe Investigation of the effect of different variables on strength of adhesive joints(WILEY, 2014-10-01) Adin, Hamit; Deniz, Mehmet EminIn this article, the tensile strength of different adhesive bonded joints under a tensile load was analyzed numerically. The effects of certain parameters, including the bonding length and bonding ratio, were investigated. For this reason, the epoxy adhesive was used. Joints were prepared with aluminum materials. The stress analyses were employed using the Finite Element Method (FEM). ANSYS (v.14.0.1) FEM tool was utilized to investigate the stress distribution characteristics of aluminum lap joint under tensile loading. Numerical results were found to be quite reasonable. The numerical results show that the influences of variations are very notable when the equivalent stresses are between 18 MPa and 20 MPa. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Öğe Environmental effects on mechanical properties of glass-epoxy composites(De Gruyter, 2014-05) Deniz, Mehmet Emin; Karakuzu, Ramazan; Kanlıoğlu, HalitThis study presents the effects of seawater and distilled water immersion time periods on mechanical properties of unidirectional glass reinforced epoxy composites. Tension, compression, and shear test specimens exposed to seawater and distilled water were prepared according to ASTM standards. After tests, SEM imaging of fracture surface of specimens was made. Results showed that seawater and distilled water immersion time affects significantly mechanical properties and strength values of glass-epoxy composites.Öğe Impactor diameter effect on low velocity impact response of woven glass epoxy composite plates(Elsevier, 2013-07) Deniz, Mehmet Emin; İçten, Bülent Murat; Gören Kıral, BinnurIn this study, the effect of impactor diameter on the impact response of woven glass–epoxy laminates has been investigated. Impact tests were performed by using Fractovis Plus test machine with four different impactor nose diameters as 12.7, 20.0, 25.4 and 31.8 mm. Specimens were impacted at various impact energies ranging from 5 J to perforation thresholds of the composite at room temperature. Variation of the impact characteristics such as the maximum contact load, maximum deflection, maximum contact time and absorbed energy versus impact energy are investigated. Results indicated that the projectile diameter highly affects the impact and Compression After Impact (CAI) response of composite materials.
