Out-of-Plane Nonlinear Dynamic Analysis of Wind Turbine Blades

2014 ◽  
Author(s):  
Venkatanarayanan Ramakrishnan ◽  
Brian F. Feeny
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Nonlinear Dynamic Analysis ◽  
Single Mode ◽  
Equation Of Motion ◽  
Wind Turbine Blades ◽  
Blade Vibration ◽  
Premature Failure ◽  
Lagrange Formulation ◽  
Out Of Plane

In this work, the out-of-plane equation of motion of a wind turbine blade modeled as a beam is developed using the Lagrange formulation. The modeling of aerodynamic loads is done with the blade element momentum theory. The equation of motion has combined effects of parametric and direct excitations and is reduced to a single mode. Perturbation analysis based on previous work shows how various terms affect the steady-state responses near resonance. Numerical simulations using parameters from a real turbine, reveal that these resonance become critical as the blades increase in size. The out-of-plane vibration model shows resonances that would not be expected by blade designers without analysis and modeling techniques presented in this work. The influence of these superharmonic blade vibration responses on the increased loads on the gearbox components would provide insight into premature failure of wind turbine blades and gearboxes.

Investigation of Discrete Out-of-Plane Waviness in Composite Wind Turbine Blades Using Ultrasonic Nondestructive Evaluation

2011 ◽  
Author(s):  
Sunil Kishore Chakrapani ◽  
Vinay Dayal ◽  
Daniel Barnard ◽  
David Hsu
Keyword(s):  
Aspect Ratio ◽  
Nondestructive Evaluation ◽  
Wind Turbine ◽  
High Frequency ◽  
Turbine Blades ◽  
Element Model ◽  
Wind Turbine Blades ◽  
Out Of Plane ◽  
Process Detection ◽  
Air Coupled Ultrasonics

With the need for larger and more efficient wind turbine blades, thicker composite sections are manufactured and waviness becomes difficult to control. Thus, there is a need for more effective and field implementable NDE. In this paper we propose a method of detection and quantification of waviness in composite wind turbine blades using ultrasonics. By employing air coupled ultrasonics to facilitate faster and easier scans, we formulated a two step process. Detection was performed with single sided air coupled ultrasonics, and characterization was performed with the help of high frequency contact probes. Severity of the wave was defined with the help of aspect ratio, and several samples with different aspect ratio waves were made. A finite element model for wave propagation in wavy composites was developed, and compared with the experimental results.

Edgewise vibration reduction of small size wind turbine blades using shunt damping

2019 ◽  
Vol 26 (3-4) ◽  
pp. 186-199
Author(s):  
Hamed Biglari ◽  
Vahid Fakhari
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Vibration Reduction ◽  
Wind Turbine Blades ◽  
Lagrange Method ◽  
Blade Vibration ◽  
Mass Damper ◽  
Horizontal Axis Wind Turbines ◽  
Shunt Damping

Edgewise vibration in wind turbine blades is one of the important factors that results in reducing the performance of wind turbines. Therefore, control or reduction of the mentioned vibrations can be of great help in increasing the efficiency of wind turbines. In this paper, the shunt damping method is proposed to reduce the edgewise blade vibration of horizontal axis wind turbines. For this purpose, partial differential equations governing dynamics of the system are derived using the Lagrange method. These equations are completely nonlinear and linearization is not performed to avoid possible errors in the analysis. In order to evaluate the effectiveness of the proposed shunt damping method in vibration reduction of the wind turbine blade, obtained results by applying shunt damping method are compared with corresponding results obtained by employing a conventional method known as a tuned mass damper (TMD). For better comparison, by considering proper cost functions, the shunt damper and TMD parameters are optimized using a genetic algorithm. Finally, the effectiveness of optimized shunt damper in vibration reduction of the blade is compared with optimized TMD by presenting simulation results.

Automated Composite Fabric Layup for Wind Turbine Blades

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Siqi Zhu ◽  
Corey J. Magnussen ◽  
Emily L. Judd ◽  
Matthew C. Frank ◽  
Frank E. Peters
Keyword(s):  
Wind Turbine ◽  
Plane Deformation ◽  
Turbine Blades ◽  
Three Dimensional ◽  
3D Models ◽  
New Method ◽  
Two Dimensional ◽  
Wind Turbine Blades ◽  
Out Of Plane ◽  
Fiberglass Fabric

This work presents an automated fabric layup solution based on a new method to deform fiberglass fabric, referred to as shifting, for the layup of noncrimp fabric (NCF) plies. The shifting method is intended for fabric with tows only in 0 deg (warp) and 90 deg (weft) directions, where the fabric is sequentially constrained and then rotated through a deformation angle to approximate curvature. Shifting is conducted in a two-dimensional (2D) plane, making the process easy to control and automate, but can be applied for fabric placement in three-dimensional (3D) models, either directly or after a ply kitting process and then manually placed. Preliminary tests have been conducted to evaluate the physical plausibility of the shifting method. Layup tests show that shifting can deposit fabric accurately and repeatedly while avoiding out-of-plane deformation.

Numerical analysis of the influence of inertial loading over morphing trailing edge devices

2018 ◽  
Vol 29 (18) ◽  
pp. 3533-3549 ◽  
Author(s):  
Nicolás G Tripp ◽  
Aníbal E Mirasso ◽  
Sergio Preidikman
Keyword(s):  
Wind Turbine ◽  
State Of The Art ◽  
Turbine Blades ◽  
External Loading ◽  
Wind Turbine Blades ◽  
Trailing Edge ◽  
Blade Vibration ◽  
Simple Estimation ◽  
Design Requirements ◽  
Inertial Loading

Larger and more flexible wind turbine blades are currently being manufactured. Those highly flexible blades suffer from loading of aeroelastic nature which increases the fatigue damage. Smart blade concepts are being developed to reduce the aerodynamic loading. The state of the art favors the discrete deformable trailing edge concept. Many authors have reported adequate performance of this type of actuators in reducing the blade vibrations. However, the question of whether the actuator can maintain its authority under strong external loading remains still answered. To solve this question, actuator models that include the loading produced by the blade vibration are required. In this article, a smart morphing trailing edge model is presented that includes the inertial forces produced by the blade dynamics. The model is applied to a commercial actuator and the influence of its parameters is analyzed. Finally, a simple estimation of the inertial loading produced by a 35-m wind turbine blade at the flutter instability condition is analyzed to understand the design requirements of this type of systems.

Simulating the Manufacturing Process and Subsequent Structural Stiffness of Composite Wind Turbine Blades with and without Defects

2012 ◽  
Vol 504-506 ◽  
pp. 249-254 ◽  
Author(s):  
Konstantine A. Fetfatsidis ◽  
Cynthia Mitchell ◽  
James A. Sherwood ◽  
Eric Harvey ◽  
Peter Avitabile
Keyword(s):  
Wind Turbine ◽  
Manufacturing Process ◽  
Turbine Blades ◽  
Hybrid Approach ◽  
Structural Stiffness ◽  
Wind Turbine Blades ◽  
Forming Process ◽  
Shell Elements ◽  
Reinforced Composite ◽  
Out Of Plane

Traditional ply-based and zone-based models are limited in their ability to account for the fiber directions resulting from the forming of fabric-reinforced composite wind turbine blades. Compounding the problem is the presence of defects such as resin-rich pockets of the polymer matrix due to out-of-plane and in-plane waves resulting from the manufacturing process. As a result, blades are typically overdesigned, unnecessarily increasing weight and material costs. In the current research, a methodology is presented for simulating the manufacturing process for fabric-reinforced composite wind turbine blades using ABAQUS/Explicit. The methodology captures the evolution of the yarn directions during the forming process thereby allowing for a map of the fiber orientations throughout the blade. A hybrid approach using conventional beam and shell elements is used to model the various fabric layers. Using experimental shear, tensile, bending, and friction data to characterize the mechanical behavior of the fabric layers, the model captures in-plane yarn waviness and changes in the in-plane yarn orientations as they conform to the shape of the mold, as well as out-of-plane wave defects as a result of the manufacturing process. Subsequently, after the fabric layers have been laid into the mold and the final yarn orientations are known, the structural stiffness of the blade resulting from the resin-infused fabrics can be calculated. The methodology can thereby link the resulting bending and torsional stiffnesses of the blade back to the manufacturing process. This paper discusses the methodology for determining the material properties of the beam and shell elements in their final orientations in the cured composite to predict the structural stiffness of a wind turbine blade.

Experiments of Wind Turbine Blades with Rocket Triggered Lightning

2009 ◽  
Vol 129 (5) ◽  
pp. 689-695
Author(s):  
Masayuki Minowa ◽  
Shinichi Sumi ◽  
Masayasu Minami ◽  
Kenji Horii
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Triggered Lightning

Folding of flexible hinges for aircraft wingtips and wind turbine blades

2021 ◽  
Author(s):  
Aileen G. Bowen Perez ◽  
Giovanni Zucco ◽  
Paul Weaver
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Wind Turbine Blades
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