Numerical and Experimental Analysis of Horizontal-Axis Wind Turbine Blade Fatigue Life (original) (raw)
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Vibrational Fatigue Analysis of NACA 63215 Small Horizontal Axis Wind Turbine blade
Materials Today: Proceedings, 2018
Wind turbines are critical in structural behaviour, which are characteristically using the wind in order to produce power. In wind machines, blades are considered to be an important component because of its critical profile at different sections, weight, and the structural parameters with relatively high amplitude and high frequency. Life-cycle estimation of wind turbines is crucial to develop their design and maintenance process, since they should have more lifespan with minimum foreign object disruptions as well as low probabilities of failures. Wind turbine is eco friendly technology; it should provide a high lifespan of its whole set up by reduces the major failure factors. Due to the effect of aerodynamic loads acts in the wind turbine blades may cause to fail at unpredictably high an amount, which creates the wind turbine to make fatigue analysis as important factors in its performance. Fatigue life and its analysis of each rotating component is one of the major factors of concern due to the terrible failures that can result from it. In this paper, the fatigue behaviour of wind turbine blade in response to different frequencies has established to the level that the prediction of working lifespan is fitting an essential part of the design process also compare the suitability of a wind turbine blade with different composite materials such as Kevlar, Glass Fiber Reinforced Plastic (GFRP) and Carbon Fiber Reinforced Plastic (CFRP) by simulates the displacement and principal stress using numerical method. The reference component of this paper is modeled by using CATIA. A numerical model of the blade was created using ANSYS Workbench 16.2 in order to estimate the typical mode shapes occurring within the blade based on a wind profile and mass approximating the location where these blades are expected to vibrate. Also, fatigue life of wind turbine blade analyzed for three composite materials and the results are compared in order to find out the optimum material body.
FATIGUE LIFE OPTIMIZATION OF WIND TURBINE BLADE
Wind Turbine is one of the most useful non-conventional energy sources in today's energy crisis scenario. But the initial cost of the Wind Turbine plant is very high. The manufacturing cost of the Wind Turbine blade is about 15-20% of the Wind Turbine plant cost. So it is likely to reduce the investment cost of the Wind Turbine blade by maximizing the service life of the Wind Turbine blades. Different types of loads acting on the Wind Turbine blade and consequential stresses developed in blade are studied. The Finite Element model of Wind Turbine blade is analyzed by using ANSYS software. Fatigue stresses are developed on the Wind Turbine blade due to change in wind speed. The maximum wind speed range (from cut-in to cut-out wind speed) is considered for design of blade as well as predicting the fatigue life of the blade. Morrow's equation is used for calculating the fatigue life of wind turbine blade. The parameters which govern the fatigue life of the blade are the chord length; blade length and the twist angle. For optimizing the fatigue life of the Wing Turbine blade, the length of blade, the chord length and the twist angle, these parameters are varied. Constrained Gradient (Steepest ascent method) method is used for fatigue life optimization of the blade. The twist angle is very sensitive to the fatigue life of the blade than the chord length and the blade length. The fatigue life increases exponentially with the increase in twist angle, while there is parabolic relation between the fatigue life of the blade and the chord length. The fatigue life decreases with increase in the blade length linearly. Due to increase in fatigue life of the blade, the cost of the wind turbine plant gets reduced with more reliability.
Journal of Materials Engineering and Performance, 2009
The problem of mechanical design, performance prediction (e.g., flap-wise/edge-wise bending stiffness, fatigue-controlled life, the extent of bending-to-torsion coupling), and material selection for a prototypical 1 MW horizontal-axis wind turbine (HAWT) blade is investigated using various computer-aided engineering tools. For example, a computer program was developed which can automatically generate both a geometrical model and a full finite-element input deck for a given single HAWT-blade with a given airfoil shape, size, and the type and position of the interior load-bearing longitudinal beam/shear-webs. In addition, composite-material laminate lay-up can be specified and varied in order to obtain a best combination of the blade aerodynamic efficiency and longevity. A simple procedure for HAWT-blade material selection is also developed which attempts to identify the optimal material candidates for a given set of functional requirements, longevity and low weight.
Fatigue Testing of the Small Wind Turbine Blade
International Journal of Mechanical Engineering and Robotics Research, 2022
Blades are the elements of a wind turbine which are the most vulnerable to destruction. Facing the unstable wind (one that changes its speed and direction), they are subjected to cyclic and fluctuating loads. This problem is particularly pronounced in case of small wind turbine (SWT) blades or blades for wind tunnel tests in scale, which are oftentimes made of anisotropic materials or manufactured in a way leading to anisotropy, like 3D-printing. SWT blades have to be designed in a way which will allow them to operate for a long time without any fracture. Hence, the fatigue strength is a key parameter, which determines their operation time and should be tested before putting a wind turbine into operation. The aim of this paper is to describe the methodology of fatigue tests of the small wind turbine blades. Next, the construction of the fatigue test stand and results of the experiment will be examined.
Applied Sciences
A comparative evaluation of the fatigue damage occurring in the blades of small wind turbines, with different power regulation schemes, has been conducted for the first time. Three representative test cases were built, one based on stall regulation and two using pitch regulation. The power curves were tuned to be identical in all cases, in order to allow for a direct comparison of fatigue damage. A methodology combining a dynamic simulation of a wind turbine forced by stochastic wind speed time series, with the application of the IEC 61400-2 standard, was designed and applied for two levels of turbulence intensity. The effect of the wind regime was studied by considering Weibull-distributed wind speeds with a variety of parameter sets. Not unexpectedly, in typical wind regimes, stall regulation led to a generally higher fatigue damage than pitch regulation, for similar structural blade design, but the practical implications were smaller than thought previously. Given the need for co...
Study of fatigue damage in wind turbine blades
Engineering Failure Analysis, 2009
The inspection of damages detected in some blades of 300 kW wind turbines revealed that the nature of these damages was probably due to a fatigue mechanism. The causes that had originated the failure (superficial cracks, geometric concentrator, abrupt change of thickness) have been studied, verifying, by means of the simplified evaluation procedure of fatigue life of the ''Germanischer Lloyd" (GL) standard, that these causes can explain the failure detected in the period of time in which it happened.
A simulation model for wind turbine blade fatigue loads
Journal of Wind Engineering and Industrial Aerodynamics, 1999
The paper describes a horizontal axis wind turbine time domain simulation and fatigue estimation program written using the Delphi2+ language. The program models the #apwise motion of a single rotor blade to determine the blade-root fatigue damage of a medium size wind turbine. The e!ects of turbulence intensity, mean wind speed, wind shear, vertical wind component, dynamic stall, stall hysteresis, and blade sti!ness were examined. When all these e!ects were simulated it is found that a reduction in life of about 2 occurs between a low wind speed low turbulence intensity site, compared to a high wind speed high turbulence intensity site.
Numerical study of the structural static and fatigue strength of wind turbine blades
Materials Today: Proceedings, 2019
Wind turbine blades are highly complex structures with complex 3 dimensional forms governed by their aerodynamics that allow a maximum of power output and efficiency. On the structural side there is always an immense interest in keeping the blades as light and as rigid as possible. No structure being perfectly rigid, the wind turbine blades are specifically designed to keep their deformation in check. Deflection twist couplings are also designed into the blades to have favorable aerodynamic properties even in the deformed state. A combination of experimental and numerical work has been used to address the most critical failure mechanisms and to get an understanding of the complex structural behavior of wind turbine blades. Different failure mechanisms observed during the tests performed for reduced scale tests (smaller test specimens) and the corresponding FE-analysis are presented.
Wind Engineering, 2019
The wind energy has been recognised as one of the rising sustainable energies in the world. The wind turbines are subjected to high aerodynamic loads and they cause vibrations due to the wake formation. The magnitude of the applied loads has significant effects on the crack propagation. The fatigue loads have been identified as one of the key sources of damage, with delamination as the main cause for the failure of the turbine blades. The article presents a review of fatigue damages that have been experienced in the wind turbine blades, and factors that are influenced due to the fatigue loads are discussed. The causes and effects of the fatigue loads have been highlighted, and the ways for preventing the fatigue damage by improving the design lifetime are mainly concentrated in review. The overall review gives an idea for determining and reducing the crack growth in wind turbine blades.