Journal of Structural Engineering & Applied Mechanics

Canan Sarıçam Nazan Okur Nuray Uçar Nevin Çiğdem Gürsoy

In this study, the effects of the addition of Activated carbon powder (ACP), Polyacrylonitrile nanofiber web (PAN), application of Plasma treatment (P), and the number of treatment layers on thermal insulation and sound absorption properties of fibrous structures have been examined and compared to each other. Bamboo and E-glass fibers have been used to produce fibrous layered structures. E-glass-based fibrous structures had slightly higher thermal resistance than that of bamboo fiber-based fibrous structures. However, sound absorption of bamboo-based fibrous layered structures was higher than that of E-glass fiber-based fibrous layered structures. The results revealed that plasma treatment, nanofiber web application, and activated carbon powder insertion increased the thermal resistance of fibrous layered structures made of bamboo fiber and E-glass fiber. In particular, the plasma treatment on three layers provided the highest thermal resistance for the E-glass fiber fibrous layered structure, however, PAN nanofiber application between three layers resulted in the highest thermal resistance for the bamboo fiber fibrous layered structure. Concerning sound absorption, the PAN nanofiber web provided the highest improvement for both the bamboo fiber-based layered structures and the E-glass-based layered structures.

https://doi.org/10.31462/jseam.2023.03224235

Engin Akçagün Nuray Öz Ceviz Abdurrahim Yılmaz

The primary aim of this study is to investigate the competitive landscape and profitability prospects of the Turkish Composite Industry. To accomplish this objective, the research employs the Five Force Model framework developed by Michael E. Porter. A survey instrument was designed to collect data from companies operating within the Turkish Composite Industry. The results reveal that the industry exhibits a low susceptibility to substitution, a moderate level of buyer bargaining power, and a medium to high level of supplier bargaining power. With the presence of both large and small firms, competition among existing competitors is deemed high, while entry barriers are considered moderate to high.

https://doi.org/10.31462/jseam.2023.03236248

Gözdenur Ulu İkilem Göcek

In this study, different types of polymeric layers were coated in different weights (g/m2) on nonwoven fabrics by extrusion process and then, sound absorption and transmission loss properties of each sample were examined. Nonwoven fabrics were produced from polyester (PET) fiber, formed by the carding process and bonded by the needle punching process. These samples were tested between 50-6000 Hz frequency range to reveal the effect of polymer layer type and weight coated on nonwoven fabrics on the sound absorption and transmission loss performance at the low, medium, and high-frequency values. Polymer layers were coated with the weight of 400 gsm and 800 gsm. Nonwoven fabric samples coated with polyethylene or polypropylene layers and nonwoven fabric samples without polymeric coating were tested by using an impedance tube and compared in terms of sound absorption and transmission loss performance. In the test system, two sides of the samples were tested separately. It was seen that the sound absorption performance of the samples changed in case the sound wave was first incident to the polymeric layer or nonwoven layer.

https://doi.org/10.31462/jseam.2023.03249256

Gülnur Başer

The widespread use of carbon-fiber-reinforced plastics (CFRP) has attracted many industries such as defense, and aerospace as well as in sailboats, automotive, and rotor-blades, where high strength-to-weight ratios are required. For the aerospace and defense customer today, the importance is no longer just on minimum weight and therefore performance, but primarily on cost of ownership. Textile-manufactured composites, particularly of non-crimp fabric (NCF) type offer significant cost savings in terms of reduced labor time and higher deposition rates over the unidirectional prepreg tape which is the most traditional method. Vacuum vacuum-assisted infusion method is the most used production technic in CFRP parts which also offers high fiber ratios. The most important goal is the impregnation of carbon fiber package in a through-the-thickness direction to get good quality parts in infusion. The behavior of the impregnability depends mainly on the out-of-plane permeability of the fabric. The fiber type, orientation of the fibers, and the stitching parameters, mainly influence the permeability of the fabric. In this study, the influence of textile parameters on the out-of-plane permeability of UD (unidirectional) carbon fiber NCF was investigated. The stitching yarn parameters (stitch pattern, stitch tension, and stitch length) were varied to see the influence on the out-of-plane permeability. The out-of-plane permeability was measured using a tailored visual flow front monitoring method by measuring resin flow distance on the X and Y axes of the fabric during infusion. The results show that the out-of-plane permeability of the UD (0°) carbon fiber NCF is significantly affected by the stitch pattern, stitch tension, and stitch length.

https://doi.org/10.31462/jseam.2023.03257263

Melis Eldem Eksen

The use of fiber-reinforced thermoplastic composite materials is increasing day by day due to their high strength and recyclability. In addition to these superior advantages, high melt viscosity is among the disadvantages of these materials because it makes reinforcement absorption difficult. This problem can be solved by using hybrid yarns in which reinforcement and thermoplastic fibers are homogeneously mixed for the production of thermoplastic composites. This study, it was aimed to prepare basalt fiber/PET hybrid yarns containing basalt fiber in different volume ratios by air-jet mixing method and to prepare thermoplastic composite materials by pressing from fabrics woven from hybrid yarns. By determining the mechanical properties of basalt fiber/PET thermoplastic composites prepared to contain basalt fiber in different proportions by volume, the effects of basalt fiber amount in hybrid yarn blends on the mechanical properties of the composite material were examined and the most appropriate basalt fiber amount was determined.

https://doi.org/10.31462/jseam.2023.03264267