Browsing by Author "Nawab, Yasir"
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Item Development and characterization of hybrid green composites from textile waste(Springer, 2018) Masood, Zaid; Nawab, Yasir; Trzcielinski, S.; Karahan, Mehmet; Karahan, Nevin; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; AAK-4298-2021; 8649952500; 22034801200The current study focused on the use of textile industry waste (cotton and jute) and glass fabric for the development of hybrid composites. Composites were fabricated using either a single reinforcement or different fractions of cotton, jute and glass fabric. A good fibre-matrix interface was observed using Scanning Electronic Microscopy (SEM). The mechanical performance of the developed composites was analyzed under certain loads. The tensile and flexural properties of the composites developed from waste material was found lower as compared to the glass fiber composites, while hybrid composites had comparable properties. Regression equations were also developed to predict the mechanical properties of the hybrid composites. The results revealed that, after some pre-treatment (mercerization and desizing) textile waste materials can be used with virgin material in reinforcement part of composite to decrease the cost but with optimum mechanical properties. This usage of textile waste will be helpful for its value addition and solving the waste disposal problems.Item Effect of silica nanoparticles on mechanical properties of Kevlar/epoxy hybrid composites(Taylor & Francis, 2019-04-03) Jabbar, Madeha; Nawab, Yasir; Ashraf, Munir; Hussain, Tanveer; Karahan, Mehmet; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; AAK-4298-2021; 8649952500The addition of nanofillers in high-performance reinforcement results in the formation of hybrid composites. The objective of this research is to determine the effect of silica nanofillers loading on the mechanical properties of Kevlar/epoxy composites for ballistic use. Produced hybrid composite laminates were tested for flexural properties, tensile Properties and impact energy absorption. DMA analyses were performed to investigate composite properties at elevated temperatures. It was observed that introduction of silica nanofillers enhanced flexural properties, tensile strength, and storage modulus of composites. Impact energy absorption was increased up to a specific extent of nanofiller addition. The findings of this study indicate that introduction of silica nanofillers on Kevlar fabrics is a promising method for enhancing mechanical properties of hybrid composite laminates.Publication Effect of structural hybridization on ballistic performance of aramid fabrics(Sage Publications, 2019-06-01) Karahan, Mehmet; Karahan, Nevin; Nasir, Muhammad Ali; Nawab, Yasir; KARAHAN, MEHMET ALİ; KARAHAN, NEVİN; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu; FEC-4798-2022; AAK-4298-2021This article presents an investigation regarding the ballistic performance of hybrid panels formed by combining woven and unidirectional (UD) para-aramid fabrics. For this purpose, hybrid panels are formed by combining woven and UD para-aramid fabrics with different ply ratios. The hybrid panels formed in this way are subjected to ballistic tests according to National Institute of Justice (NIJ) standard. The results show that hybrid panels present 4.48% less trauma depth as compared to 100% woven fabric panels and 3% less trauma diameter as compared to 100% UD fabric panels. Furthermore, 13.9% less energy is transmitted to the back side of hybrid panels as compared to 100% UD fabric panels. The energy absorbed per unit weight in hybrid panels is 8.48% more as compared to 100% woven fabrics. Additionally, in wet conditions, less trauma depth of hybrid panels is observed as compared to both 100% woven and 100% K-Flex UD fabric panels. No significant difference is realized in trauma diameter between hybrid panels and 100% woven fabric panels in wet conditions. However, 3.25% less trauma diameter is noticed in hybrid panels as compared to 100% UD fabric panels.Item Experimental analysis of ILSS of glass fibre reinforced thermoplastic and thermoset textile composites enhanced with multiwalled carbon nanotubes(Korean Society of Mechanical Engineers, 2018-09-13) Zahid, Saamia; Nasir, Muhammad Ali; Nauman, Saad; Nawab, Yasir; Ali, H. M.; Khalid, Yasir; Nabeel, Muhammad; Ullah, Mudaser; Karahan, Mehmet; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu/Tekstil, Giyim, Ayakkabı ve Deri Bölümü.; AAK-4298-2021; 8649952500In this study experimental investigation of interlaminar shear strength of glass fibre reinforced thermoplastic polyurethane (TPU) and epoxy based thermosets composites enhanced with multi walled carbon nanotubes (MWCNTs) is presented, and comparison is made between thermoplastic and thermosets composites. Suspension of MWCNTs in TPU and epoxy matrix was prepared using magnetic stirring and sonication technique. Both thermoplastic reinforced glass fibre and thermosets reinforced glass fibre composites were manufactured using hand layup technique. Carbon nanotubes were added in the concentrations of 0.1 %weight, 0.3 %weight and 0.5 %weight in both types of composites. Results showed that as the concentration of CNTs increases, the ILSS of the nanocomposites was also improved. With an addition of 0.5 % weight CNTs, there was improvement of 24.37 % in ILSS in epoxy based composites and 10.05 % enhancement in thermoplastic polyurethane reinforced glass fibre composites. The average ILSS obtained for thermoplastic polyurethane composites was less than that of epoxy composites. The TPU based composites also demonstrated inelastic deformations without any trace of brittle fracture. The pristine epoxy based composites on the other hand did show inelastic deformations followed by brittle fracture. Higher concentrations of MWCNTs led to an absence of brittle fracture during the tests, owing to the crack bridging effect of the CNTs.Item Interdependence of moisture, mechanical properties, and hydrophobic treatment of jute fibre-reinforced composite materials(Taylor & Francis, 2017-01-18) Ameer, Muhammad Haris; Shaker, Khubab; Ashraf, Munir; Nawab, Yasir; Ahmad, Sheraz; Nasir, Muhammad Ali; Karahan, Mehmet; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; AAK-4298-2021; 8649952500Despite cheap and sustainable in nature, the use of natural fiber composites is limited due to their high moisture absorption, poor fiber-matrix interface, and lack of data on evolution of properties when subjected to environmental factor such as temperature and humidity. The aim of this research is to study the interdependence of moisture regain, hydrophobic treatment, and the mechanical properties of jute fiber-reinforced composite materials. Composite samples made from treated and untreated jute fiber-reinforced composites were exposed to humid environment and their moisture regain, mechanical properties and fiber-matrix interface was tested at given time intervals until four weeks. The composites produced with hydrophobic treated reinforcement showed lesser moisture regain and improvement in the tensile and flexural strengths compared to untreated fabric composite. A clear improvement in fiber-resin interface was observed by scanning electronic microscopy. The dynamic mechanical analysis of treated and untreated composites was conducted in a temperature range 20-140 degrees C. An increase in the storage modulus of treated composite materials was noted as compared to untreated ones. Furthermore, it was concluded that developed composite loss their mechanical properties linearly with immersion time. However, this aging was slow in treated fabric composites especially hybrid fluorocarbon and fluorocarbon.Publication Investigation of impact properties of para-aramid composites made with a thermoplastic-thermoset blend(Sage Publications, 2021-06-01) Khan, Muhammad Imran; Umair, Muhammad; Hussain, Rizwan; Karahan, Mehmet; Nawab, Yasir; KARAHAN, MEHMET; Bursa Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu; AAK-4298-2021During impact, thermoset composites show brittle behaviour, whereas thermoplastic composites show a relatively ductile behaviour with higher absorption of impact energy. The research on the investigation of the impact performance of composites with thermoplastic resin and/or with a blend of thermoplastic and thermoset resins found rare. In the present study, both thermoset (phenolic, vinyl ester) and thermoplastic (Polyvinyl butyral - PVB) matrices were used with Para-aramid reinforcement for the development of five-layered composite samples. Drop weight impact, Charpy impact, flexural (three-point), and hardness tests were conducted to assess the performance of the composite samples. The developed thermoplastic composites showed superior impact properties as compared to thermoset composites except for out-of-plane deformation (trauma). This deformation was reduced using a blend of PVB and Phenolic. The composite made with blend absorbs 8-9% more energy as compared to Phenolic composites with almost the same value of trauma. Overall, damage area is also lesser in the case of composite made using a blend. The experimental results are validated by one-way ANOVA (Tukey) statistical analysis.Item Investigation of mechanical behavior of woven/knitted hybrid composites(Taylor & Francis, 2016-11-06) Ashraf, Waqas; Nawab, Yasir; Umair, Muhammad; Shaker, Khubab; Karahan, Mehmet; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; AAK-4298-2021; 8649952500The objective of this research is to develop the woven/knitted hybrid composites for improved in plane as well as out of plane mechanical properties. Two different type of structures and two different materials were used in this study. Firstly, the woven and knitted fabrics were developed with glass and Kevlar yarn. Secondly, the laminated composite samples were fabricated with different stacking sequence of fabric plies. The epoxy resin was used as matrix. The cured samples were characterized for impact, tensile and dynamic mechanical properties. The behavior of composite materials was then analyzed with percentages of different fiber and fabric types. The samples with higher percentages of knitted reinforcement gave better impact strength but failed to provide better tensile properties. Moreover, the samples with higher percentages of woven structure and glass materials gives better modulus values.Item Mechanical behaviour of hybrid composites developed from textile waste(Inst Chemical Fibres, 2018) Masood, Zaid; Ahmad, Sheraz; Umair, Muhammad; Shaker, Khubab; Nawab, Yasir; Karahan, Mehmet; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu/Tekstil Teknolojisi Anabilim Dalı.; AAK-4298-2021; 8649952500The current study focused on the use of textile industry waste (cotton and jute) and glass fabric for the development of hybrid composites. Composites were fabricated using either a single reinforcement or different fractions of cotton, jute and glass fabric. A good fibre-matrix interface was observed using Scanning Electronic Microscopy (SEM). The mechanical performance of the composites developed was analysed under certain loads. The tensile and flexural properties of the composites developed from waste material was found lower as compared to the glass fiber composites, while hybrid composites had comparable properties. Regression equations were also developed to predict the mechanical properties of the hybrid composites. Dynamic Mechanical Analysis (DMA) results revealed that after some pre-treatment (mercerization and desizing) textile waste materials can be used with virgin material in the reinforcement part of the composite to decrease the cost, but with optimum mechanical properties.Item Mechanical response of novel 3D woven flax composites with variation in z yarn binding(Taylor & Francis, 2020-06-02) Jabbar, Madeha; Nawab, Yasir; Ashraf, Munir; Hussain, Tanveer; Karahan, Mehmet; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; AAK-4298-2021; 8649952500This paper is focused on the development of novel 3D woven flax composites for improved mechanical performance. The 3D woven interlock fabrics were produced on dobby loom using novel weaving patterns, with variation in binding point density (four different levels). These fabric structures were then used to fabricate composites with green epoxy resin as a matrix. Tensile, flexural, short beam shear, impact (pendulum and drop weight) and compression after impact properties were characterized. It was found that 3D woven composites having higher binding point density showed overall improved mechanical behavior, i.e. the out-of-plane properties were enhanced whereas in-plane properties are either reduced or unaffected.Item Static and dynamic mechanical properties of cotton/epoxy green composites(Inst Chemical Fibres, 2016) Koyuncu, Menderes; Shaker, Khubab; Nawab, Yasir; Karahan, Mehmet; Karahan, Nevin; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu.; 0000-0003-0379-7492; AAG-8536-2021; AAK-4298-2021; 8649952500; 22034801200A study on the effect of alkaline treatment on the mechanical properties of cotton fabric reinforced epoxy composites is presented in this paper. One hour treatment of cotton fabric was performed using three different concentrations of sodium hydroxide (NaOH) solution. 1% NaOH treated fabric reinforced composites exhibited maximum improvement in tensile strength. It was concluded that the said NaOH concentration improves interfacial adhesion between the cotton fabric and epoxy resin. Moreover the morphology of the fracture surface, evaluated by scanning electron microscopy (SEM), indicated that surface treatment can yield better adhesion between the fabric and matrix, demonstrating the effectiveness of the treatment. The dynamic mechanical analysis (DMA) results revealed that alkali treated (1% and 3% NaOH) fabric composites exhibit higher storage moduli and glass transition temperature (Tg) values as compared to the untreated fabric composites. However, for all the composite specimens, the storage modulus decreased with increasing temperature (25 -100 degrees C). Tg values of 50.9, 56.7, 52.8 and 37.7 degrees C were recorded for the untreated and (1%, 3% and 5%) treated composites, respectively. The tan delta values decreased for all the composites with increasing temperature, indicating enhanced interactions between the polymer matrix and fabric reinforcement.Item Study of dynamic compressive behaviour of aramid and ultrahigh molecular weight polyethylene composites using Split Hopkinson Pressure Bar(Sage Puplications, 2017-01) Shaker, Khubab; Jabbar, Abdul; Nawab, Yasir; Karahan, Mehmet; Karahan, Nevin; Uludağ Üniversitesi/Meslek Yüksekokulu/Teknik Bilimler Yüksekokulu.; AAK-4298-2021; 8649952500; 22034801200In this paper, high strain rate compression properties of aramid and ultrahigh molecular weight polyethylene composites in the out-of-plane direction are tested at room temperature on a Split Hopkinson Pressure Bar apparatus. Tests were conducted on composites reinforced with woven or Uni-Directional (UD) fabrics made from aramid or ultrahigh molecular weight polyethylene as well as on composites reinforced with hybrid reinforcement. The strain rate is varied in the tests by changing the projectile shooting pressure. Four different pressures 2, 4, 6 and 8 bar were selected to change the strain rate. Stress-strain and energy absorption behaviour of eight type of samples were noted. Hybrid samples showed better performance in the energy absorption compared with other samples.Item Study of influence of interlocking patterns on the mechanical performance of 3D multilayer woven composites(SAGE Publications, 2018-04) Umair, Muhammad; Hamdani, Syed Talha Ali; Asghar, Muhammad Ayub; Hussain, Tanveer; Nawab, Yasir; Ali, Mumtaz; Karahan, Mehmet; Uludağ Üniversitesi/Teknik Bilimler Meslek Yüksekokulu/Tekstil Teknolojisi Anabilim Dalı.; AAK-4298-2021; 8649952500Three-dimensional multilayer woven composites are mostly used in high-performance applications due to their excellent out-of-plane mechanical performance. The current research presents an experimental investigation on the mechanical behavior of three-dimensional orthogonal layer-to-layer interlock composites. The glass filament yarn and carbon tows were used as reinforcement in warp and weft directions respectively, whereas epoxy was used as a resin for composite fabrication. Three different types of orthogonal layer to layer interlock namely warp, weft, and bi-directional interlock composites were fabricated and the effect of interlocking pattern on their mechanical performance was evaluated. The evaluation of the mechanical performance was made on the basis of tensile strength, impact strength, flexural strength, and dynamic mechanical analysis of composites in warp and weft directions. It was found that warp and weft interlock composites showed better tensile behavior as compared to bi-directional interlock composite both in the warp and weft directions, due to the presence of less crimp as compared to the bi-directional interlockcomposite. However, the bi-directional interlock composite exhibited considerably superior impact strength and three-point bending strength as compared to the other structures under investigation. These superior properties of bi-directional interlock composites were achieved by interlocking points in warp and weft directions simultaneously, creating a more compact and isotropic structure. Tan delta values of dynamic mechanical analysis results showed that bi-directional interlockcomposite displayed the highest capacity of energy dissipation in the warp and weft directions while weft interlock structures displayed highest storage and loss moduli in the warp direction.