Comparison Between Inclusions and Holes as Stress Raisers in Composite Materials Used in Wind Turbine Components

2007 ◽  
Author(s):  
Mohamed Elshabasy ◽  
Mohamed Abouelwafa ◽  
Alaa Hamdy ◽  
Ayman Elmidany
Keyword(s):  
Composite Materials ◽  
Wind Turbine ◽  
Materials Used ◽  
As Stress ◽  
Stress Raisers

scholarly journals Theoretical study on the efficiency of utilization of nanoclay-CFRP composite materials in the root area of wind turbine blades

10.30544/397 ◽  
2018 ◽  
Vol 24 (4) ◽  
Author(s):  
Layth Sayyid Salman Al-Rukaibawi ◽  
Miodrag J Lukic
Keyword(s):  
Composite Materials ◽  
Wind Turbine ◽  
Theoretical Calculations ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Reinforced Polymers ◽  
Root Area ◽  
Carbon Fibre Reinforced Polymers ◽  
Cfrp Composite ◽  
Materials Used

In this study, theoretical calculations were performed to determine the most efficient utilization of nanoclays added as reinforcement for CFRP composite materials used for wind turbine blade manufacture. Four different V39 blade models were created, and numerical simulations by FEA were performed. Glass Fibre Reinforced Polymers (GFRP), whole model made of Carbon Fibre Reinforced Polymers/nanoclay (2%) (CFRPN2), Hybrid Glass and Carbon/nanoclay (2%) (HGCN2) and Hybrid Glass and Carbon/nanoclay (5%) (HGCN5). The targeted part was the joining zone between the root and the blade. The most important finding to emerge from this study is that the modest addition of nanoclay (2%) with carbon fiber reinforced polymer leads to a significant stiffer blade, with a minimal deflection, about 70% lower than GFRP. Furthermore, the HGCN2 model is considered to be safer as it has a lower stress concentration than others (52.84 kN/m2). It can be considered that the probability of failure of the entire root area will be decreased if nanoclay-CFRP hybrid blades are used, yielding higher durability and lower overall costs. These findings contribute to decisions related to materials selection, structural, aerodynamic design and layup schedule choice.

Use of composite materials and hybrid composites in wind turbine blades

2021 ◽  
Author(s):  
Sri Sai P. Reddy ◽  
Rohan. Suresh ◽  
Hanamantraygouda. M.B. ◽  
B.P. Shivakumar
Keyword(s):  
Composite Materials ◽  
Wind Turbine ◽  
Hybrid Composites ◽  
Turbine Blades ◽  
Wind Turbine Blades

Effect of Bubble Inclusions on the Mechanical Properties of Cast Poly-Methyl Metacrylate

1972 ◽  
Vol 94 (4) ◽  
pp. 847-852 ◽  
Author(s):  
J. D. Stachiw
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Loading Condition ◽  
Stress Raiser ◽  
Compressive Yield Strength ◽  
Compressive Test ◽  
Acrylic Plastic ◽  
Methyl Metacrylate ◽  
As Stress ◽  
Stress Raisers

Bubble inclusions present in cast acrylic plastic generally degrade the mechanical properties of the material. To evaluate the effect of bubbles on the mechanical strength of acrylic plastic, 120 tensile and compressive test specimens were machined from massive acrylic castings with bubble inclusions. The specimens were tested under uniaxial loading condition and effect of bubbles on tensile and compressive strength noted. The stress raiser effect of bubbles caused the tensile specimens to fail at stresses 7 to 30 percent lower than observed in specimens without bubbles. The compressive yield strength was not affected by bubbles. However, here the bubbles served as stress raisers also and caused cracks to initiate at the bubble surfaces when the yield strength of acrylic plastic was reached.

Surface Charging Considerations for Composite Materials Used in Spacecraft Applications

2015 ◽  
Vol 43 (9) ◽  
pp. 2901-2906
Author(s):  
Justin J. Likar ◽  
Robert E. Lombardi ◽  
Alexander L. Bogorad ◽  
Roman Herschitz
Keyword(s):  
Composite Materials ◽  
Surface Charging ◽  
Materials Used

scholarly journals APPLICATIONS AND ADVANCES OF THE ACTIVE THERMOGRAPHY FOR THE INSPECTION OF COMPOSITE MATERIALS USED IN INDUSTRY

2018 ◽  
Author(s):  
Marcella Grosso ◽  
Sergio D. Soares ◽  
Isabel C. P. Maragarit-Mattos ◽  
Gabriela R. Pereira
Keyword(s):  
Composite Materials ◽  
Active Thermography ◽  
Materials Used

scholarly journals The Effects of Physical Properties of Fibers in Nettle Fiber/Polyester Composites on the Thermal Conductivity Coefficient

2018 ◽  
Vol 1 (1) ◽  
pp. 834-842
Author(s):  
Murat Koru ◽  
Kenan Büyükkaya
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Physical Properties ◽  
Thermal Conductivity Coefficient ◽  
The Black Sea ◽  
Stinging Nettle ◽  
Fiber Concentration ◽  
Black Sea Region ◽  
Polyester Composites ◽  
Materials Used

The physical properties of the materials used are also important in the thermal conduction, besides many other factors. In this study, nettle fiber/polyester composites were formed using stinging nettle grown in the Black Sea region. The stinging nettle fibers used in the formation of these composites were divided into three parts as bottom, middle, and top. The physical properties (diameter, density, crystallinity) of the fibers obtained from different parts of the plant and how the increased fiber concentration affected the thermal conductivity coefficients of the composite materials formed were studied. As a result, it was observed that the thermal conductivity coefficients of the composites increased with the increase of the crystallinity ratio of the fiber. Moreover, the increased fiber concentration significantly increased the thermal conductivity coefficient of the composite materials produced.

The Interface Crack Between Dissimilar Anisotropic Composite Materials

1983 ◽  
Vol 50 (1) ◽  
pp. 169-178 ◽  
Author(s):  
S. S. Wang ◽  
I. Choi
Keyword(s):  
Composite Materials ◽  
Interface Crack ◽  
Hilbert Problem ◽  
Stress Singularity ◽  
Anisotropic Elasticity ◽  
Crack Model ◽  
Closed Crack ◽  
Anisotropic Composite ◽  
Interlaminar Crack ◽  
As Stress

The fundamental nature of an interface crack between dissimilar, strongly anisotropic composite materials under general loading is studied. Based on Lekhnitskii’s stress potentials and anisotropic elasticity theory, the formulation leads to a pair of coupled governing partial differential equations. The case of an interlaminar crack with fully opened surfaces is considered first. The problem is reduced to a Hilbert problem which can be solved in a closed form. Oscillatory stress singularities are observed in the asymptotic solution. To correct this unsatisfactory feature, a partially closed crack model is introduced. Formulation of the problem results in a singular integral equation which is solved numerically. The refined model exhibits an inverse square-root stress singularity for commonly used advanced fiber-reinforced composites such as a graphite-epoxy system. Extremely small contact regions are found for the partially closed interlaminar crack in a tensile field and, therefore, a simplified model is proposed for this situation. Physically meaningful fracture mechanics parameters such as stress intensity factors and energy release rates are defined. Numerical examples for a crack between θ and −θ graphite-epoxy composites are examined and detailed results are given.

Sign in / Sign up

Export Citation Format

Share Document