scholarly journals ARTIFICIAL SPECIMENS MANUFACTURING OF GLASS FIBRE REINFORCED COMPOSITE FOR SUB-SURFACE DEFECTS INSPECTION BY ACTIVE LONG-PULSE THERMOGRAPHY

10.6036/10168 ◽  
2021 ◽  
Vol 96 (6) ◽  
pp. 586-590
Author(s):  
JOSE GUADALUPE RICO ESPINO ◽  
JOSE LUIS COLIN MARTINEZ ◽  
ISAIAS ALVARADO MEDRANO ◽  
GERARDO RODRIGUEZ HERNANDEZ ◽  
CAROLINA RETA CASTRO
Keyword(s):  
Composite Materials ◽  
Surface Defects ◽  
Low Cost ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Pulse Thermography ◽  
Glass Fibre Reinforced ◽  
Long Pulse ◽  
Induced Defects ◽  
Non Destructive

The detection and analysis of sub-surface defects in composite materials specimens have been problems of interest in recent years in different industries. For instance, in the wind industry, such materials are used for manufacturing wind turbine blades. A variety of defects can occur inside composite materials, e.g., porosities, fibre rupture, and inclusions. This work presents the design and manufacturing of artificial test specimens of composite material, to which specific defects were induced in a non-destructive way. The used manufacturing process was VARTM. In addition, a method to localise and characterise induced defects is proposed. Such method works by applying active long-pulse thermography to the test specimens. Further, we show that both the proposed low-cost optical system and the long-pulse active thermography technique allow the non-destructive thermal analysis of parts to detect sub-surface defects in composite materials based on fiberglass reinforced epoxy resin

scholarly journals Infrared thermography used for composite materials

2018 ◽  
Vol 191 ◽  
pp. 00011
Author(s):  
Abdelaziz Mouahid
Keyword(s):  
Composite Materials ◽  
Infrared Thermography ◽  
Low Cost ◽  
Turbine Blades ◽  
Infrared Camera ◽  
Unit Weight ◽  
Material Surface ◽  
Wind Turbine Blades ◽  
Active Thermography ◽  
Non Destructive

Many areas of the industry use composite materials, because of their good mechanical features in terms of low density and high mechanical strength. Composite materials are used wherever elevated rigidity and strength with reduced unit weight are required; such as wind turbine blades, shipbuilding, aeronautical and aerospace. However, the properties of composites can be hugely affected because of inside defaults such as delaminations or local cracks. Several non-destructive methods have been used for the verification of defects during construction or operation, such as ultrasound or x-ray. These methods are costly and difficult to implement. Non-destructive method using infrared thermography is considered very useful and works perfect with low cost. Two methods of non-destructive detection by infrared exists, which are (i) passive thermography, that consists of measuring infrared stream emitted by the material and (ii) active thermography, which consists of heating the material and measuring the cooling of material surface using an infrared camera. This communication describes the basic principles of both passive and active thermography, and then describes other different methods for detection of composite materials defects.

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

scholarly journals Probabilistic Design of Wind Turbine Blades with Treatment of Manufacturing Defects as Uncertainty Variables in a Framework

2017 ◽  
Author(s):  
Trey W. Riddle ◽  
Jared W. Nelson ◽  
Douglas S. Cairns
Keyword(s):  
Wind Turbine ◽  
Probabilistic Models ◽  
Low Cost ◽  
Turbine Blades ◽  
Design Parameters ◽  
State University ◽  
Wind Turbine Blades ◽  
Manufacturing Defects ◽  
Montana State University ◽  
Blade Failure

Abstract. Given that wind turbine blades are such large structures, the use of low-cost composite manufacturing processes and materials has been necessary for the industry to be cost competitive. Since these manufacturing methods can lead to inclusion of unwanted defects, potentially reducing blade life, the Blade Reliability Collaborative tasked the Montana State University Composites Group with assessing the effects of these defects. Utilizing the results of characterization and mechanical testing studies, probabilistic models were developed to assess the reliability of a wind blade with known defects. As such, defects were found to best be assessed as design parameters in a parametric probabilistic analysis allowing for establishment of a consistent framework to validate categorization and analysis. Monte Carlo simulations were found to adequately describe the probability of failure of composite blades with included defects. By treating defects as random variables, the approaches utilized indicate the level of conservation used in blade design may be reduced when considering fatigue. In turn, safety factors may be reduced as some of the uncertainty surrounding blade failure is reduced when analysed with application specific data. Overall, the results indicate that characterization of defects and reduction of design uncertainty is possible for wind turbine blades.

Investigation of performance of small wind turbine blades with winglets

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Michal Kulak ◽  
Michal Lipian ◽  
Karol Zawadzki
Keyword(s):  
Wind Turbine ◽  
Low Cost ◽  
Turbine Blades ◽  
Significant Degree ◽  
Small Scale ◽  
Performance Study ◽  
Wind Turbine Blades ◽  
Content Type ◽  
Efficiency Increase ◽  
Energy Prosumers

Purpose This paper aims to discuss the results of the performance study of wind turbine blades equipped with winglets. An investigation focusses on small wind turbines (SWTs), where the winglets are recalled as one of the most promising concepts in terms of turbine efficiency increase. Design/methodology/approach To investigate a contribution of winglets to SWT aerodynamic efficiency, a wind tunnel experiment was performed at Lodz University of Technology. In parallel, computational fluid dynamics (CFD) simulations campaign was conducted with the ANSYS CFX software to investigate appearing flow structures in greater detail. Findings The research indicates the potential behind the application of winglets in low Reynolds flow conditions, while the CFD study enables the identification of crucial regions influencing the flow structure in the most significant degree. Research limitations/implications As the global effect on a whole rotor is a result of a small-scale geometrical feature, it is important to localise unveiled phenomena and the mechanisms behind their generation. Practical implications Even the slightest efficiency improvement in a distributed generation installation can promote such a solution amongst energy prosumers and increase their independence from limited natural resources. Originality/value The winglet-equipped blades of SWTs provide an opportunity to increase the device performance with relatively low cost and ease of implementation.

Damage in Composite Material: A Microwave Detection

2014 ◽  
Vol 605 ◽  
pp. 303-305
Author(s):  
Jerome Rossignol ◽  
Alain Thionnet
Keyword(s):  
Composite Materials ◽  
Composite Structures ◽  
Dielectric Material ◽  
Low Cost ◽  
Unidirectional Composite ◽  
Microstrip Resonator ◽  
Microwave Frequencies ◽  
Fibre Break ◽  
Materials Used ◽  
Non Destructive

In the field of the transport, the increase of the security rule recommends to a periodic control of the structure to detect damage due to mechanical loadings. Now, current materials, used in the case of transport applications, are the composite materials. The methods, to control these materials or composite structures, need to be low cost, non-destructive, in-situ and swiftness as far as possible. The scientific literature reports many methods to control the damage in composite materials and structures. However the above requirements and the adaptation to composite materials reduce the number of methods that can be used. Currently, the adapted methods are based on infrared thermography, acoustical emission, EMIR (ElectroMagnetic InfraRed) or microwave imagery. We present an innovative non-destructive method of detecting damages in composite materials. The method is based on the observation and analysis of the modification in dielectric material resulting from damage. The originality of this method is that the diagnostic is obtained by using a microstrip resonator at microwave frequencies. The feasibility of the method is demonstrated by the detection of a fibre break into an unidirectional composite submitted to a flexural loading. The fibre break is the damage to detect. The perspective of this work is to develop a quantification and a localization of damages.

Fatigue properties of a glass-fibre-reinforced polyester material used in wind turbine blades

1998 ◽  
Vol 33 (3) ◽  
pp. 183-193
Author(s):  
J Vázquez ◽  
A Silvera ◽  
F Arias ◽  
E Soria
Keyword(s):  
Wind Turbine ◽  
Fatigue Limit ◽  
Glass Fibre ◽  
Moisture Absorption ◽  
Turbine Blades ◽  
Fatigue Properties ◽  
Dynamic Tests ◽  
Wind Turbine Blades ◽  
Static Tests ◽  
Glass Fibre Reinforced

Glass-fibre-reinforced polyester (GFRP) is a composite commonly used in the manufacture of wind turbine blades. In the present work, one such material has been subject to static and dynamic tests in order to obtain data that can be applied to the design of wind turbine blades and other machine elements. The results of the static tests established a basis for the determination of a set of tension-tension (constant amplitude and sinusoidal load) dynamic tests with the aim of establishing a mathematical model in order to predict life as a function of the load state and calculate the fatigue limit. The multiplicative model (y = axb) for y = log of life and x = transformed stress (a and b are characteristic parameters of the material obtained from data) matches the data quite well. The conclusion is that the GFRP studied has no fatigue limit. The possible decrease of fatigue strength of the material with solar radiation and moisture absorption was also investigated, with a negative result.

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