Using a two-stage approach to improving accuracy of resonance fatigue tests for large-scale wind turbine blades

2019 ◽  
Vol 11 (4) ◽  
pp. 043301
Author(s):  
Jinbo Zhang ◽  
Kezhong Shi ◽  
Xingxing Li ◽  
Ke Yang
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Turbine Blades ◽  
Fatigue Tests ◽  
Wind Turbine Blades ◽  
Two Stage ◽  
Improving Accuracy

scholarly journals A Robot-Assisted Large-Scale Inspection of Wind Turbine Blades in Manufacturing Using an Autonomous Mobile Manipulator

2021 ◽  
Vol 11 (19) ◽  
pp. 9271
Author(s):  
Heiko Engemann ◽  
Patrick Cönen ◽  
Harshal Dawar ◽  
Shengzhi Du ◽  
Stephan Kallweit
Keyword(s):  
Wind Turbine ◽  
Rotor Blade ◽  
Large Scale ◽  
Turbine Blades ◽  
Rotor Blades ◽  
Mobile Manipulator ◽  
Wind Turbine Blades ◽  
Left Hand ◽  
Planning Strategy ◽  
Execution Strategy

Wind energy represents the dominant share of renewable energies. The rotor blades of a wind turbine are typically made from composite material, which withstands high forces during rotation. The huge dimensions of the rotor blades complicate the inspection processes in manufacturing. The automation of inspection processes has a great potential to increase the overall productivity and to create a consistent reliable database for each individual rotor blade. The focus of this paper is set on the process of rotor blade inspection automation by utilizing an autonomous mobile manipulator. The main innovations include a novel path planning strategy for zone-based navigation, which enables an intuitive right-hand or left-hand driving behavior in a shared human–robot workspace. In addition, we introduce a new method for surface orthogonal motion planning in connection with large-scale structures. An overall execution strategy controls the navigation and manipulation processes of the long-running inspection task. The implemented concepts are evaluated in simulation and applied in a real-use case including the tip of a rotor blade form.

scholarly journals Fatigue in Fiber-Metal Laminates for Small Wind Turbine Blades Application

2018 ◽  
Vol 165 ◽  
pp. 07005
Author(s):  
Wei Sai ◽  
Gin Boay Chai
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Maximum Load ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Wind Condition ◽  
Wind Turbine Blades ◽  
Operation Condition ◽  
Small Wind Turbine ◽  
Fiber Metal

A methodology to study the fatigue of a wind turbine blade in a 10KW small wind turbine is proposed in this paper. Two working conditions (namely normal fatigue operation condition and extreme wind condition) are considered based on IEC61400-2. The maximum load calculated from both cases were used as a reference to perform material sample fatigue study. Fiber-metal laminate – GLARE 3/2 with a centre 1mm notch on the external aluminium layers was modelled based on fracture mechanics approach to calculate the stress intensity factor and fatigue crack growth rate at maximum applied stress of 240Mpa. GLARE panel fabrication and tensile tests were included. The fatigue tests were performed on unnotched samples with stress range from 80Mpa to 300Mpa and plotted into S-N curve.

Parametric Stiffness in Large-Scale Wind-Turbine Blades and the Effects on Resonance and Speed Locking

2020 ◽  
Author(s):  
Ayse Sapmaz ◽  
Brian F. Feeny
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Turbine Blades ◽  
Relative Strength ◽  
Wind Turbine Blades ◽  
Fixed Position ◽  
Horizontal Axis Wind Turbine ◽  
Parametric Effect ◽  
Parametric Effects ◽  
Blade Tip

Abstract This paper is on parametric effect in large scale horizontal-axis wind-turbine blades and speed locking phenomenon for a simplified model of the in-plane blade-hub dynamics. The relative strength of the parametric stiffness is evaluated for actual and scaled-length blades. Fixed-position natural frequencies are found at different rotation angles to show the significance of the gravity’s parametric effect. The ratio of the parametric and elastic modal stiffness is then estimated for the scaled versions of the NREL’s blades for four models to present the relation between the blade size and the parametric effects. The parametric effect on blade tip placements are investigated for superharmonic resonances at orders two and three for blades of various lengths. An analysis of speed-locking is presented, and interpreted for the various blades.

Evaluation of dual-axis fatigue testing of large wind turbine blades

2011 ◽  
Vol 226 (7) ◽  
pp. 1693-1704 ◽  
Author(s):  
Peter R Greaves ◽  
Robert G Dominy ◽  
Grant L Ingram ◽  
Hui Long ◽  
Richard Court
Keyword(s):  
Service Life ◽  
Wind Turbine ◽  
Fatigue Testing ◽  
Turbine Blades ◽  
Bending Moment ◽  
Fatigue Tests ◽  
Simulation Software ◽  
Wind Turbine Blades ◽  
Moment Distribution ◽  
Large Wind

Full-scale fatigue testing is part of the certification process for large wind turbine blades. That testing is usually performed about the flapwise and edgewise axes independently but a new method for resonant fatigue testing has been developed in which the flapwise and edgewise directions are tested simultaneously, thus also allowing the interactions between the two mutually perpendicular loads to be investigated. The method has been evaluated by comparing the Palmgren–Miner damage sum around the cross-section at selected points along the blade length that results from a simulated service life, as specified in the design standards, and testing. Bending moments at each point were generated using wind turbine simulation software and the test loads were designed to cause the same amount of damage as the true service life. The mode shape of the blade was tuned by optimising the position of the excitation equipment, so that the bending moment distribution was as close as possible to the target loads. The loads were converted to strain–time histories using strength of materials approach, and fatigue analysis was performed. The results show that if the bending moment distribution is correct along the length of the blade, then dual-axis resonant testing tests the blade much more thoroughly than sequential tests in the flapwise and edgewise directions. This approach is shown to be more representative of the loading seen in service and can thus contribute to a potential reduction in the weight of wind turbine blades and the duration of fatigue tests leading to reduced cost.

scholarly journals Full-scale fatigue tests of CX-100 wind turbine blades. Part II: analysis

2012 ◽  
Author(s):  
Stuart G. Taylor ◽  
Hyomi Jeong ◽  
Jae Kyeong Jang ◽  
Gyuhae Park ◽  
Kevin M. Farinholt ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Fatigue Tests ◽  
Full Scale ◽  
Wind Turbine Blades

Nonlinear Dynamics of a Rotary Energy Harvester With a Double Frequency Up-Conversion Mechanism

2020 ◽  
Vol 15 (9) ◽  
Author(s):  
Saman Nezami ◽  
Soobum Lee
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Energy Harvester ◽  
Turbine Blades ◽  
Physical Contact ◽  
Wind Turbine Blades ◽  
Double Frequency ◽  
Coupled Equations ◽  
Piezoelectric Energy ◽  
Cantilevered Beam

Abstract This paper develops a mathematical model of a two degree-of-freedom piezoelectric energy harvester (PEH) in which vibration is driven by disk swing motion. The proposed device converts slow mechanical rotation into piezoelectric vibration using gravity force and magnetic repelling force. The harvester consists of a disk and a piezoelectric cantilevered beam. The disk with an unbalanced mass swings on a rotating object (e.g., wind turbine blade) and two magnets attached to both the beam and the disk can transfer the kinetic energy of the disk to the beam without physical contact. The energy method is used to derive three coupled equations to model the motion of the disk, vibration of the beam, and the piezoelectric voltage output. The effect of harvester orientation on power generation performance is studied as the rotational speed changes, and the simulation results are experimentally verified. Possible application of this energy harvester to a power-sustainable sensor node for large-scale wind turbine blades monitoring is discussed.

Visual Similarity to Aid Alternative-Use Concept Generation for Retired Wind-Turbine Blades

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
E. Kwon ◽  
A. Pehlken ◽  
K.-D. Thoben ◽  
A. Bazylak ◽  
L. H. Shu
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Large Scale ◽  
Turbine Blades ◽  
Visual Similarity ◽  
Concept Generation ◽  
Wind Turbine Blades ◽  
Similar Images ◽  
Disposal Options ◽  
New Framework

The challenge of finding alternative uses for retired wind-turbine blades, which have limited disposal options, motivates this work. Two reuse concept-generation activities (CGAs) conducted in German universities revealed difficulties with the parts' large scale and seeing beyond their original use. Existing methods, e.g., using functional analogy, are less applicable, since for safety reasons, these parts should not be reused to fulfill the same function. Therefore, this work explores the use of visual similarity to support reuse-concept generation. A method was developed that (1) finds visually similar images (VSIs) for wind-turbine-blade photos and (2) derives potential-reuse concepts based on objects that are visually similar to wind-turbine blades in these images. Comparing reuse concepts generated from the two methods, VSI produced fewer smaller-than-scale concepts than CGA. While other qualities such as feasibility depend on the specific photo selected, this work provides a new framework to exploit visual similarity to find alternative uses. As demonstrated for wind-turbine blades, this method aids in generating alternative-use concepts, especially for large-scale objects.

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