Bend-Twist Coupling Design and Evaluation of Spar Cap of Wind Turbine Compliance Blade

2010 ◽  
Vol 139-141 ◽  
pp. 1400-1405
Author(s):  
Wang Yu Liu ◽  
Yong Zhang
Keyword(s):  
Wind Turbine ◽  
Volume Fraction ◽  
Coupling Effect ◽  
Coupling Parameter ◽  
Dynamic Performance ◽  
Von Mises Stress ◽  
Hybrid Fibers ◽  
Fiber Volume ◽  
Plane Shear ◽  
The Impact

The bend-twist coupling design method of spar cap of 1.5MW wind turbine blade made by biased hybrid fibers is discussed, and the coupling parameter is established. It is found that flap-twist coupling effect is only related to the laminated materials, not sensitive to the geometry shape. When varying the angle of off-axis carbon fibers from 7.5° to 30° and the volume fraction from 10% to 90%, different bend-twist coupling effect can be obtained. The results show that the optimal angle of spar cap is closer to 18°, and of skins are about 13°. When constraints, such as fibers strain, the in-plane shear stress and Von Mises stress of static index, are added on the blade, the spar cap is optimized with about 45% carbon fiber volume fraction and 18° off-axis angle. Finally, the impact of natural frequencies of dynamic performance on the blade design is proved to be inessential.

The Adaptive Blade Design and Evaluation of Wind Turbine

2010 ◽  
Vol 97-101 ◽  
pp. 2318-2323
Author(s):  
Wang Yu Liu ◽  
Jia Xing Gong ◽  
Xi Feng Liu ◽  
Xin Zhang
Keyword(s):  
Wind Turbine ◽  
Medial Axis ◽  
Coupling Effect ◽  
Design Method ◽  
Von Mises Stress ◽  
Blade Design ◽  
Adaptive Performance ◽  
Laminar Shear Stress ◽  
Von Mises ◽  
The Impact

This article explored the design method of the wind turbine blade being of flapping-twist adaptive performance and how to evaluate its feasibility and reliability according to the comprehensive factors. The results indicate that both spar cap and skin with off-axis carbon fiber can achieve the efficient flapping-twist coupling effect. Through overall investigation, the results show that the maximum fiber strains of tensile and compressive go up with increase of the off-axis angle, and the peak inter-laminar shear stress increase more rapidly. While, all of these evaluating indicators should be kept in the reference range for used materials. Moreover, when the off-axis angle increases, the peak Von Mises stress declines. In addition, the impact of natural frequencies on the blade design is proved to be insignificant. Finally, utilizing the medial axis laminates in the blade decoupled area is helpful to strengthen the blade fatigue resistivity.

Effect of surface density and fiber length on the porosity and permeability of nonwoven flax reinforcement

2017 ◽  
Vol 88 (15) ◽  
pp. 1776-1787 ◽  
Author(s):  
Mohamed Habibi ◽  
Édu Ruiz ◽  
Gilbert Lebrun ◽  
Luc Laperrière
Keyword(s):  
Pore Size ◽  
Surface Density ◽  
Fiber Length ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Short Fiber ◽  
Fiber Volume ◽  
Fibrous Network ◽  
Porosity And Permeability ◽  
The Impact

This paper presents an experimental study and modeling of the influence of surface density and fiber length on the permeability of novel nonwoven flax fiber manufactured by the paper making process. Firstly, the relation between surface density, fiber lengths and pore size distribution measured with a porometer capillary instrument is reported in this study. The results show that higher surface density gives a denser fibrous network with a low porosity rate and longer fiber decreases the total number of fibers and increases the pore size for a given surface density. A liquid permeability study was then carried out to identify the impact of surface density, short fiber length and fiber volume fraction on in-plane impregnation of the reinforcement. Permeability was found to be inversely proportional to the reinforcement of surface density. In contrast, an increase of the fiber length increases the in-plane permeability of the reinforcement. Finally, a mathematical modeling is proposed to predict the permeability behavior of these innovative natural fiber webs.

scholarly journals Impact and shear properties of carbon fabric/ poly-dicyclopentadiene composites manufactured by vacuum‐assisted resin transfer molding

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 437-443 ◽  
Author(s):  
Hyeong Min Yoo ◽  
Moo Sun Kim ◽  
Bum Soo Kim ◽  
Dong Jun Kwon ◽  
Sung Woong Choi
Keyword(s):  
Impact Strength ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Resin Transfer Molding ◽  
Maximum Shear Stress ◽  
Weight Percent ◽  
Fiber Volume ◽  
Shear Properties ◽  
Transfer Molding ◽  
The Impact

AbstractDicyclopentadiene (DCPD) resin has gained popularity owing to its fast curing time and ease of processing with a low viscosity in the monomer state. In the present study, the impact and shear properties of a carbon fiber (CF)/p-DCPD composite were investigated. The CF/p-DCPD composite was manufactured by vacuum-assisted resin transfer molding with CF as the reinforcement and p-DCPD as the resin with a maximum fiber volume fraction of 55 weight percent. Impact and shear properties of the CF/p-DCPD composite were evaluated and compared with those of a CF/Epoxy composite. The maximum shear stress and modulus of the CF/p-DCPD composite were lower than that of the CF/Epoxy composite. However, the CF/p-DCPD composite had higher toughness than that of the CF/Epoxy composite; this indicates that it is tougher and exhibits a more ductile load-displacement response with a lower modulus and larger failure deformation. The impact strength of the CF/p-DCPD composite was about three time that of the CF/Epoxy composite. The higher impact strength of the CF/p-DCPD composite is attributed to the resin characteristics: epoxy resin has a more brittle behavior, and hence, higher energy is required for crack propagation due to fracture.

PENGARUH VARIASI FRAKSI VOLUME KOMPOSIT POLYESTER-SERAT KULIT JAGUNG (Zea Mays) TERHADAP KEKUATAN IMPAK, BENDING, DAN TARIK

2016 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Akhmad Syarief ◽  
Muhammad Amin
Keyword(s):  
Zea Mays ◽  
Volume Fraction ◽  
Natural Fibers ◽  
Corn Fiber ◽  
Bending Test ◽  
Fiber Volume ◽  
Test Volume ◽  
Corn Husk ◽  
The Many ◽  
The Impact

One of the engineering materials is Composite. Composite is a material formed from a combination of two or more matrials that have stronger mechanical properties than the. The composite consists of two parts: a matrix as a binder or a composite protector and a filler as a composite filler. Natural fibers are an alternative filler, and the corn husk fiber (Zea Mays) is one of the many natural fibers grown in the Tanah Laut area of South Kalimantan.From the result of the research, the effect of volume fraction on the composite has the fiber skin fiber which has the highest strength for the impact price that is on the fiber with the volume fraction of 1% 99% fiber polyester corn fiber fiber which has the impact price of 0.0338 joule / mm2. In the highest strength bending test that is on the composite with a fraction of fiber volume of 3% that has a bending power of 3,5775MPa. And in composite tensile test, volume fraction 4% fiber 96% polyester and 5% fiber 95% polyrster have the same value of highest strength that is tensile pull of 1,7991 MPa.

Experimental Study on Impact Behavior of Flax Fiber Reinforced PP Laminates

2011 ◽  
Vol 332-334 ◽  
pp. 735-738 ◽  
Author(s):  
Li Yan Liu ◽  
Yong Liang Han ◽  
Fei Zhang
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Flax Fiber ◽  
Impact Behavior ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Technical Parameters ◽  
The Impact

This paper is aiming to research the impact behavior of flax fiber reinforced PP laminates considering the end use of the products. Flax yarn and Polypropylene (PP) filaments were twisted together with three fiber volume fraction 0.45, 0.50 and 0.60 to form the commingled yarns which were woven into fabrics as prepreg with plain and twill structures respectively. The prepregs of different layers were pressed into flax reinforced PP composites in the process of hot-pressing. The laminates with different fiber volume fraction, layer, and woven structure were tested and analyzed respectively aiming at the impact resistibility in succession. SEM micrograph of the impact fracutured surface was observed and analyzed as well. The results reveal that the impact properties of laminates with twill structures are prior to those of laminates with plain structures when other technical parameters are the same. The ability of impact resistibility of flax reinforced PP laminates improves with the increase of the fibre volume fraction, layer amount and impact velocity respectively in this research.

Analysis of Bending Behavior of Laminated Composite Beam

2015 ◽  
Vol 786 ◽  
pp. 421-425
Author(s):  
R. Arravind ◽  
M. Saravanan ◽  
K. Balasubramanian
Keyword(s):  
Composite Beam ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Laminated Composite ◽  
Layered Composite ◽  
Fiber Volume ◽  
Bottom Side ◽  
Bending Behavior ◽  
Laminated Composite Beam ◽  
The Impact

This paper discusses about the impact of fiber volume fraction on the bending behavior of a laminated composite beam. A two layered composite beam with upper layer made of glass fiber epoxy resin and reinforced with Kevlar at the bottom side of the beam is modeled and structural analysis is carried out. The analysis shows that the tensile strength increases with increase in fiber volume fraction. The compression strength decreases with increase in fiber volume fraction in the upper fiber where as increases in the bottom fiber and the obtained results are correlating with the experimental and analytical studies.

scholarly journals Peningkatan Sifat Mekanik Komposit Serat Alam Limbah Sabut Kelapa (Cocofiber) yang Biodegradable

2021 ◽  
Vol 6 (1) ◽  
pp. 30-37
Author(s):  
Sri Hastuti ◽  
Herru Santosa Budiono ◽  
Diki Ilham Ivadiyanto ◽  
Muhammad Nurdin Nahar
Keyword(s):  
Mechanical Properties ◽  
Fiber Volume Fraction ◽  
Bending Strength ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Composites ◽  
Coconut Fiber ◽  
Fiber Volume ◽  
Coconut Coir ◽  
The Impact

Inovasi baru serat dari sabut kelapa dimanfaatkan untuk meningkatkan nilai ekonomis dari serat sabut kelapa, oleh karena itu dirancanglah pendayagunaan serat dari sabut kelapa untuk penguat komposit dengan material serat alam yang biodegradable. Hal ini untuk mendukung penggunaan komposit yang ramah terhadap lingkungan dan mengurangi penggunaan material komposit serat sintetis yang polutan. Tujuan penelitian adalah menganalisis sifat mekanik pada komposit serat alam bermaterial serat dari sabut kelapa yang ramah lingkungan. Metode penelitian pembuatan komposit berpenguat serat dari sabut kelapa dilakukan treatment NaOH 15% selama 5 jam dan fraksi volume serat 10 %, 15 %, dan 20 %. Komposit  serat dari sabut kelapa dengan matriks UPRs 157 BQTN dengan hardener MEXPO. Pengujian mekanik dilakukan uji bending menggunakan standar ASTM D790 dan uji impak  menggunakan standar ASTM D5941.  Pengujian impak komposit serat alam menunjukkan ketangguhan impak komposit pada fraksi volume serat 20% dengan nilai 0.017588J/mm2. Hasil pengujian menunjukkan peningkatan fraksi volume serta berpengaruh terhadap peningkatan kekuatan bending komposit serat dari sabut kelapa  dengan kekuatan optimum bending pada fraksi volume serat 10% dengan nilai 44,33N/mm2. Hal ini menunjukkan peningkatan fraksi volume serat dengan perendaman NaOH 15% akan meningkatkan sifat mekanik bending dan impak komposit. Perendaman NaOH memberikan pengaruh daya serap sabut kelapa terhadap matrik Unsaturated Polyester yang dapat meningkatkan daya rekat antara penguat serat dengan matrik sehingga meningkatkan sifat mekanik bending dan impak komposit. ABSTRACT The innovation of coco fiber is used to increase the economic value of coconut coir, therefore the utilization of coconut fiber for reinforcing composites with biodegradable natural fiber material is designed. This is to support the use of composites that are friendly to the environment and reduce the use of pollutant synthetic fiber composite materials. The research objective was to analyze the mechanical properties of natural fiber composites with environmentally friendly coconut fiber as material. The research method of making fiber-reinforced composites from coconut coir was carried out by 15% NaOH treatment for 5 hours and a fiber volume fraction of 10%, 15%, and 20%. Composite fiber from coconut coir with UPRs 157 BQTN matrix with MEXPO hardener. Mechanical testing is carried out using the ASTM D790 standard and the impact test using the ASTM D5941 standard. The impact test of natural fiber composites showed the impact toughness of the composite at a fiber volume fraction of 20% with a value of 0.017588 J/ mm2. The test results showed an increase in volume fraction and an effect on the increase in the bending strength of coconut fiber composites with the optimum bending strength at a fiber volume fraction of 10% with a value of 44.33N /mm2. This shows that the increase in fiber volume fraction by immersion in 15% NaOH will increase the bending mechanical properties and the impact of the composite. Soaking NaOH has an effect on the absorption power of coconut coir on the Unsaturated Polyester matrix which can increase the adhesion between the fiber reinforcement and the matrix thereby increasing the bending mechanical properties and impact of the composite.

Irradiation Duration Effect of Gamma Ray on the Compressive Strength of Reactive Powder Concrete

2020 ◽  
Vol 857 ◽  
pp. 15-21
Author(s):  
Nesreen B. Najib ◽  
Shatha D. Mohammed ◽  
Wasan Z. Majeed ◽  
Nada Mahdi Fawzi A. Jalawi
Keyword(s):  
Compressive Strength ◽  
Fiber Volume Fraction ◽  
Gamma Ray ◽  
Volume Fraction ◽  
Reactive Powder Concrete ◽  
Fiber Volume ◽  
Gamma Ray Irradiation ◽  
Duration Effect ◽  
Reactive Powder ◽  
The Impact

Reactive Powder Concrete (RPC) could be considered as the furthermost significant modern high compressive strength concrete. In this study, an experimental investigation on the impact of micro steel fiber volume fraction ratio and gamma ray irradiation duration influence upon the compressive strength of RPC is presented. Three volume fraction ratios (0.0, 1.0 and 1.5) % was implemented. For each percentage of the adopted fiber ratios, six different irradiation duration was considered; these are (1, 2, 3, 4, 5 and 6) days. Gamma source (Cs-137) of energy (0.662) MeV and activity (6) mci was used. In a case of zero volume fraction ratio, the experimental results showed that gamma ray had a significant influence on the reducing of the compressive strength varies between (1.2-8.6)% for a period of (1-6) days, respectively. Although there was a decrease in the compressive strength for a state of non-zero volume fraction ratio (1 and 1.5) % varies between (1.0-3.1 and 0.4-1.6) %, respectively, the attained results indicated that gamma ray had no significant effect to reduce the compressive strength of the RPC that’s included micro steel fibers as a volume fraction.

Manufacturing Modeling of Three-Dimensional Resin Injection Pultrusion Process Control Parameters for Polyester/Glass Rovings Composites

2006 ◽  
Vol 129 (1) ◽  
pp. 143-156 ◽  
Author(s):  
A. L. Jeswani ◽  
J. A. Roux
Keyword(s):  
Process Parameters ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Fiber Reinforcement ◽  
Resin Flow ◽  
Molding Process ◽  
Fiber Volume ◽  
Liquid Resin ◽  
Pultrusion Process ◽  
The Impact

Pultrusion, sometimes referred to as continuous resin transfer molding process, is a continuous, cost-effective method for manufacturing composite materials with constant cross sections (such as rod stock, beams, channels, and tubing). The objective of this study is to improve the fiber reinforcement wetout and thus the quality of the pultruded part in the injection pultrusion process. The complete wetout of the dry reinforcement by the liquid resin depends on various design and process parameters. The process parameters modeled in this study are fiber pull speed, fiber volume fraction, and viscosity of the resin. In the present work, a three-dimensional finite volume technique is employed to simulate the liquid resin flow through the fiber reinforcement in the injection pultrusion process. The numerical model simulates the flow of polyester resin through the glass rovings and predicts the impact of the process parameters on wetout, resin pressure field, and resin velocity field. The location of the liquid resin flow front has been predicted for an injection slot as well as for five discrete injection ports.

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