ORCID Profile
0000-0002-3096-0366
Current Organisation
Eskişehir Osmangazi University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Springer Science and Business Media LLC
Date: 05-2016
Publisher: Springer Science and Business Media LLC
Date: 04-2018
Publisher: Elsevier BV
Date: 10-2019
Publisher: Springer Science and Business Media LLC
Date: 25-10-2019
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 2017
Publisher: Trans Tech Publications, Ltd.
Date: 16-11-2021
DOI: 10.4028/WWW.SCIENTIFIC.NET/AEF.43.33
Abstract: This paper presents the feasibility of developing an electromechanical in-situ viscosity measurement technique by analyzing the detectability of small variations in the viscosity of different shear thickening fluids and their different compositions. Shear thickening fluid (STF) is a kind of non-Newtonian fluid showing an increasing viscosity profile under loading. STF is utilized in several applications to take advantage of its tunable rheology. However, process control in different STF applications requires rheological measurements, which cause a costly investment and long-lasting labor. Therefore, one of the most commonly used in-situ structural health monitoring techniques, electromechanical impedance (EMI), was used in this study. In order to actuate the medium electromechanically, a piezoelectric wafer active sensor (PWAS) was used. The variations in the spectral response of PWAS resonator that can be submerged into shear thickening fluid are analyzed by the root mean square deviation, mean absolute percentage deviation and correlation coefficient deviation. According to the results, EMI metrics provide good correlations with the rheological parameters of STF and thereby enabling quick and low-cost rheological control for STF applications such as vibration d ers or stiffness control systems.
Publisher: Springer Science and Business Media LLC
Date: 04-2019
Publisher: Trans Tech Publications, Ltd.
Date: 11-2017
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.880.132
Abstract: High performance fabrics are preferable for armor systems due to their lightweight structure and flexibility. High performance fabrics are generally used in body armor design for personal protection. However, these fabrics are utilized to cover the living space in military vehicles such as helicopters and armored vehicles. Besides, pilot seats in combat helicopters are included in utilization area of high performance fabrics. On the other hand armor is defined as a defensive covering to protect body or something against attacking threats. Protection is provided by absorbing the kinetic energy of the attacking threats and stopping them before any damage occurs in the target. This paper offers an overview of high performance fabrics in armor systems.
Publisher: Springer Science and Business Media LLC
Date: 15-09-2020
Publisher: MDPI AG
Date: 08-06-2023
Abstract: In this study, we fabricated an intelligent material, shear stiffening polymer (SSP), and reinforced it with carbon nanotube (CNT) fillers to obtain intelligent mechanical and electrical properties. The SSP was enhanced with multi-functional behavior, such as electrical conductivity and stiffening texture. Various amounts of CNT fillers were distributed in this intelligent polymer up to a loading rate of 3.5 wt%. The mechanical and electrical aspects of the materials were investigated. Regarding the mechanical properties, dynamic mechanical analysis was carried out, as well as conducting shape stability and free-fall tests. Viscoelastic behavior was investigated in the dynamic mechanical analysis, whereas cold-flowing and dynamic stiffening responses were studied in shape stability and free-fall tests, respectively. On the other hand, electrical resistance measurements were carried out to understand the conductive behavior of the polymers of the electrical properties. Based on these results, CNT fillers enhance the elastic nature of the SSP while initiating the stiffening behavior at lower frequencies. Moreover, CNT fillers provide higher shape stability, hindering the cold flow in the material. Lastly, SSP gained an electrically conductive nature from the CNT fillers.
Publisher: Springer Science and Business Media LLC
Date: 02-04-2019
Publisher: IOP Publishing
Date: 14-02-2019
Publisher: Elsevier BV
Date: 09-2019
Publisher: Trans Tech Publications, Ltd.
Date: 02-2019
DOI: 10.4028/WWW.SCIENTIFIC.NET/JNANOR.56.63
Abstract: In this paper, a non-Newtonian fluid was fabricated dispersing nanosized silica particles in a polyethylene glycol medium. The rheology of the suspension was investigated in a stress-controlled rheometer under increasing shear rate. Based on the rheological measurements, the suspension exhibited shear thickening behavior which gives a drastic viscosity grow with the increase in the shear rate. In order to investigate the role of the micro-sized additive particles on the rheology of silica based suspension, silicon nitride particles were included in the suspension with three different concentrations. The results were discussed in terms of important parameters for the shear thickening mechanism such as critical shear rate, peak viscosity, thickening ratio and initial viscosity. According to the results, shear thickening behavior can be controlled altering the amount of silicon nitride particles in the suspension.
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier
Date: 2021
Publisher: Springer Science and Business Media LLC
Date: 06-01-2021
Publisher: Elsevier BV
Date: 03-2020
Publisher: Trans Tech Publications, Ltd.
Date: 02-2021
DOI: 10.4028/WWW.SCIENTIFIC.NET/AEF.39.9
Abstract: Ultrasonic inspection is a well-known method in non-destructive testing. Based on the changes in the ultrasonic sound speed, tested materials are evaluated in terms of internal defects. In addition to flaw detection, ultrasonic testing is used in the material characterization of ductile cast iron. Graphite shape detection has been widely investigated by ultrasonic inspection in literature. However, most of the measurements has been conducted at single frequencies. In this work, three different nodulizer included casting operations were carried out to produce ductile cast irons having various graphite morphologies. A wide frequency range of 1.25-10 MHz was selected in the ultrasonic inspection. In addition to graphite morphology analyses, the relationship between ultrasonic sound speed and mechanical properties was studied. In the mechanical analyses, hardness and tensile testing properties were investigated for the specimens. From the results, ultrasonic sound speed exhibits a considerable dependency to the graphite morphology. In addition to a good graphite detection capability, ultrasonic inspection exhibits promising results for predicting the mechanical properties such as hardness, elastic modulus, yield strength and tensile strength. It is also found that there is a slight increase in the ultrasonic sound speed by increasing the frequency, although sound speed is independent from this parameter.
Publisher: Elsevier BV
Date: 12-2017
Publisher: Springer Science and Business Media LLC
Date: 25-06-2018
Publisher: Springer Nature Switzerland
Date: 11-10-2023
Publisher: Elsevier BV
Date: 12-2017
Publisher: SAGE Publications
Date: 08-2019
Abstract: Shear thickening fluids have been extensively utilized in composite laminate structures to enhance the impact resistance in the last decade. Despite the contribution of shear thickening fluids to the protective systems, the mechanism behind the energy absorption behavior of shear thickening fluids is not fully understood. In the present study, various configurations of composite laminates were prepared and these structures were investigated under low velocity stab conditions. Contrary to the common idea of shear thickening fluid impregnation for fabrics, shear thickening fluids were used in bulk form and by means of this, pure contribution of shear thickening behavior to the energy absorption was investigated. To hold the bulk shear thickening fluids in the composite laminates, Lantor Soric SF honeycomb layers were filled with shear thickening fluids and Twaron fabrics were plied in the structures as the reinforcement. As a result of this study, it is stated that shear thickening behavior is insufficient to effectively improve the energy absorption performance of composite laminates however, shear thickening fluids are beneficial to fabric based composites because the inter-yarn friction of fabrics is enhanced using shear thickening fluids as an impregnation agent rather than a bulk form.
Publisher: Elsevier
Date: 2016
Publisher: MDPI AG
Date: 09-11-2022
Abstract: Lightweight structures with high energy absorption capacity are in high demand for energy absorption applications in a variety of engineering fields, such as aerospace, automotive, and marine engineering. Anti-impact composites are made of energy-absorbing materials that are incorporated into structures to protect the occupant or sensitive components against strikes or falls. This study deals with an experimental investigation of multi-layer composites consisting of cork and warp-knitted spacer fabrics (WKSF) for anti-impact applications. Composites were designed and created with a laser cutting machine in eight different configurations. To measure the energy absorption of the manufactured composite s les, a low-velocity drop-tower machine was designed, and the maximum reaction force due to the strike of the impactor on the specimens was measured by a dynamometer located under the s les. Moreover, energy absorption and specific energy absorption capacities were calculated for each specimen. In the final part of this study, the Life Cycle Assessment (LCA) of the designed composites was calculated to understand the eco-friendly properties of the composites.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Springer Science and Business Media LLC
Date: 16-03-2020
Publisher: Springer Science and Business Media LLC
Date: 29-10-2020
Publisher: SAGE Publications
Date: 27-05-2019
Abstract: Fatigue crack growth and corrosion are the two important failure mechanisms for aircraft structural components and, therefore, various treatments have been developed to improve the fatigue and corrosion resistance of aircraft materials. In the present study, thermo-mechanical and retrogression and re-aging treatments were applied to AA7075T7352 specimens, which were extracted from a nearly 40 years in-service F-4 Phantom component. The in-service component was selected in order to observe the influence of thermo-mechanical and retrogression and re-aging treatments on the properties of a used aircraft material and it was expected that the service life of the material is extended in the maintenance stage. In the experimental work, electrical, mechanical, fatigue crack growth, and corrosion tests were carried out using the specimens with T7352 (as-received), thermo-mechanical and retrogression and re-aging conditions. Based on the results, fatigue crack growth resistance of the material benefited from the thermo-mechanical and retrogression and re-aging treatments however, both treatments lowered the corrosion resistance of the material.
Publisher: Springer Science and Business Media LLC
Date: 10-09-2021
Publisher: Elsevier BV
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 22-11-2019
Publisher: Springer Science and Business Media LLC
Date: 07-02-2018
Publisher: Springer Science and Business Media LLC
Date: 11-2017
Publisher: FapUNIFESP (SciELO)
Date: 2019
Abstract: This paper investigates the influences of three different input parameters, such as feed rate, insert nose radius, and insert coating methods, in the turning operation of Inconel 718. The coating methods were selected as medium temperature chemical vapor deposition (MT-CVD) and physical vapor deposition (PVD) and in addition to coating methods, the role of various coating materials was discussed since the inserts were coated with multi-layers of TiCN/Al2O3/TiN and single-layer of TiAlN on carbide substrates. The results were discussed in terms of wear behavior of cutting tools and surface quality of the workpiece, which is indicated by surface roughness. A full factorial experimental design was employed in the present work and the results were evaluated using main effects plots. Furthermore, the analysis of variance (ANOVA) method was applied to specify both reactive and non-reactive effects of experimental parameter reactions. The results showed that surface roughness is reduced using low feed rates and large nosed inserts in the operations. Furthermore, TiAlN-coated inserts with PVD method provided better surface finish than with MT-CVD method. It was also found that surface roughness increases as the wear rate of inserts increases.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 04-2020
Publisher: Springer Science and Business Media LLC
Date: 23-11-2021
Publisher: Elsevier BV
Date: 09-2019
Publisher: SAGE Publications
Date: 05-10-2022
DOI: 10.1177/14644207221130316
Abstract: In this study, failure analysis of an axle shaft in an airport ground support vehicle was carried out to determine failure mechanism, failure root causes and preventive actions. Macroscopic observation, numerical analysis, metallographic analysis, chemical composition analysis, hardness measurement and tensile test methods were used in failure analysis. In numerical fatigue analyses, axle shaft was modelled as a functionally graded material due to mechanical properties changing in the material radial section as a result of induction surface hardening. The analysis results showed that the failure mechanism of fractured axle shaft was torsional fatigue. High surface roughness and insufficient mechanical properties were found as failure root causes. Making finish cut with low depth and even grinding in surface finishing process were proposed as a prevention to increase surface quality, reduce surface roughness and stress concentrations in machining of axle shaft. In addition, using another material with higher yield strength (EN 37Cr4) was proposed instead of EN 34Cr4 alloy steel as the axle shaft material.
Publisher: IOP Publishing
Date: 05-02-2019
Publisher: Elsevier BV
Date: 08-2016
Publisher: Wiley
Date: 03-11-2020
DOI: 10.1002/APP.50245
Publisher: Springer Science and Business Media LLC
Date: 2017
Publisher: Springer Science and Business Media LLC
Date: 03-2019
Publisher: Informa UK Limited
Date: 13-09-2017
Publisher: Elsevier BV
Date: 10-2019
Publisher: Springer Science and Business Media LLC
Date: 11-10-2017
Start Date: 2020
End Date: 2023
Funder: European Commission
View Funded ActivityStart Date: 2020
End Date: 2021
Funder: Türkiye Bilimsel ve Teknolojik Araştirma Kurumu
View Funded ActivityStart Date: 2020
End Date: 2021
Funder: Eskişehir Osmangazi Üniversitesi
View Funded Activity