A modified composite fatigue damage model considering stiffness evolution for wind turbine blades

2020 ◽  
Vol 233 ◽  
pp. 111736 ◽  
Author(s):  
Hongwei Liu ◽  
Zhichun Zhang ◽  
Hongbo Jia ◽  
Yanju Liu ◽  
Jinsong Leng
Keyword(s):  
Wind Turbine ◽  
Fatigue Damage ◽  
Turbine Blades ◽  
Damage Model ◽  
Wind Turbine Blades

Life prediction of wind turbine blades using multi-scale damage model

2021 ◽  
pp. 073168442199588
Author(s):  
Sepideh Aghajani ◽  
Mohammadreza Hemati ◽  
Shams Torabnia
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Fatigue Damage ◽  
Life Prediction ◽  
Turbine Blades ◽  
Damage Model ◽  
Fatigue Loading ◽  
Multiaxial Fatigue ◽  
Wind Turbine Blade ◽  
Wind Turbine Blades

Wind turbine blade life prediction is the most important parameter to estimate the power generation cost. Due to the price and importance of wind blade, many experimental and theoretical methods were developed to estimate damages and blade life. A novel multiaxial fatigue damage model is suggested for the life prediction of a wind turbine blade. Fatigue reduction of fiber and interfiber characteristics are separately treated and simulated in this research. Damage behavior is considered in lamina level and then extended to laminate; hence, this model can be used for multidirectional laminated composites. The procedure of fatigue-induced degradation is implemented in an ABAQUS user material subroutine. By applying the fatigue damage model, life is estimated by the satisfaction of lamina fracture criteria. This model provides a comprehensive idea about how damage happens in wind blades regarding a multi-axis fatigue loading condition.

Design and Fatigue Performance of Large Utility-Scale Wind Turbine Blades

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Peter K. Fossum ◽  
Lars Frøyd ◽  
Ole G. Dahlhaug
Keyword(s):  
Wind Turbine ◽  
Fatigue Damage ◽  
Turbine Blades ◽  
Fiber Material ◽  
Fatigue Performance ◽  
Wind Turbine Blades ◽  
Additional Material ◽  
Turbulent Wind ◽  
Fatigue Damage Accumulation ◽  
Utility Scale

Aeroelastic design and fatigue analysis of large utility-scale wind turbine blades have been performed to investigate the applicability of different types of materials in a fatigue environment. The blade designs used in the study are developed according to an iterative numerical design process for realistic wind turbine blades, and the software tool FAST is used for advanced aero-servo-elastic simulations. Elementary beam theory is used to calculate strain time series from these simulations, and the material fatigue is evaluated using established methods. Following wind turbine design standards, the fatigue evaluation is based on a turbulent wind load case. Fatigue damage is estimated based on 100% availability and a site-specific annual wind distribution. Rainflow cycle counting and Miner's sum for cumulative damage prediction is used together with constant life diagrams tailored to actual material S-N data. Material properties are based on 95% survival probability, 95% confidence level, and additional material safety factors to maintain conservative results. Fatigue performance is first evaluated for a baseline blade design of the 10 MW NOWITECH reference wind turbine. Results show that blade damage is dominated by tensile stresses due to poorer tensile fatigue characteristics of the shell glass fiber material. The interaction between turbulent wind and gravitational fluctuations is demonstrated to greatly influence the damage. The need for relevant S-N data to reliably predict fatigue damage accumulation and to avoid nonconservative conclusions is demonstrated. State-of-art wind turbine blade trends are discussed and different design varieties of the baseline blade are analyzed in a parametric study focusing on fatigue performance and material costs. It is observed that higher performance material is more favorable in the spar-cap construction of large blades which are designed for lower wind speeds.

scholarly journals Evaluation of Fatigue Damage for Wind Turbine Blades Using Acoustic Emission

2015 ◽  
Vol 35 (3) ◽  
pp. 179-184
Author(s):  
Hyun-Sup Jee ◽  
No-Hoe Ju ◽  
Cheal Ho So ◽  
Jong-Kyu Lee
Keyword(s):  
Acoustic Emission ◽  
Wind Turbine ◽  
Fatigue Damage ◽  
Turbine Blades ◽  
Wind Turbine Blades

Fatigue Damage Monitoring of Wind Turbine Blades by Using the Kalman Filter

AIAA Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Nobuo Namura ◽  
Kazuo Muto ◽  
Yosuke Ueki ◽  
Ryo Ueta ◽  
Norio Takeda
Keyword(s):  
Kalman Filter ◽  
Wind Turbine ◽  
Fatigue Damage ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Damage Monitoring

scholarly journals Time-Lapse Helical X-ray Computed Tomography (CT) Study of Tensile Fatigue Damage Formation in Composites for Wind Turbine Blades

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2340 ◽  
Author(s):  
Ying Wang ◽  
Lars Mikkelsen ◽  
Grzegorz Pyka ◽  
Philip Withers
Keyword(s):  
Computed Tomography ◽  
Wind Turbine ◽  
Fatigue Damage ◽  
Turbine Blades ◽  
Time Lapse ◽  
Ex Situ ◽  
Wind Turbine Blades ◽  
Damage Mechanisms ◽  
X Ray ◽  
X Ray Computed

Understanding the fatigue damage mechanisms in composite materials is of great importance in the wind turbine industry because of the very large number of loading cycles rotor blades undergo during their service life. In this paper, the fatigue damage mechanisms of a non-crimp unidirectional (UD) glass fibre reinforced polymer (GFRP) used in wind turbine blades are characterised by time-lapse ex-situ helical X-ray computed tomography (CT) at different stages through its fatigue life. Our observations validate the hypothesis that off-axis cracking in secondary oriented fibre bundles, the so-called backing bundles, are directly related to fibre fractures in the UD bundles. Using helical X-ray CT we are able to follow the fatigue damage evolution in the composite over a length of 20 mm in the UD fibre direction using a voxel size of (2.75 µm)3. A staining approach was used to enhance the detectability of the narrow off-axis matrix and interface cracks, partly closed fibre fractures and thin longitudinal splits. Instead of being evenly distributed, fibre fractures in the UD bundles nucleate and propagate locally where backing bundles cross-over, or where stitching threads cross-over. In addition, UD fibre fractures can also be initiated by the presence of extensive debonding and longitudinal splitting, which were found to develop from debonding of the stitching threads near surface. The splits lower the lateral constraint of the originally closely packed UD fibres, which could potentially make the composite susceptible to compressive loads as well as the environment in service. The results here indicate that further research into the better design of the positioning of stitching threads, and backing fibre cross-over regions is required, as well as new approaches to control the positions of UD fibres.

Optimized Constant-Life Diagram for the Analysis of Fiberglass Composites Used in Wind Turbine Blades

2005 ◽  
Vol 127 (4) ◽  
pp. 563-569 ◽  
Author(s):  
Herbert J. Sutherland ◽  
John F. Mandell
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Damage Model ◽  
Wind Farms ◽  
Materials Testing ◽  
Optimum Number ◽  
Wind Turbine Blades ◽  
Design Standards ◽  
Fiberglass Composite ◽  
Nonlinear Damage Model

Mandell et al. have recently presented an updated constant-life diagram (CLD) for a fiberglass composite that is a typical wind turbine blade material. Their formulation uses the MSU/DOE fatigue data base to develop a CLD with detailed S-N information at 13 R-values. This diagram is the most detailed to date, and it includes several loading conditions that have been poorly represented in earlier studies. Sutherland and Mandell have used this formulation to analyze typical loads data from operating wind farms and the failure of coupons subjected to spectral loading. The detailed CLD used in these analyses requires a significant investment in materials testing that is usually outside the bounds of typical design standards for wind turbine blades. Thus, the question has become: How many S-N curves are required for the construction of a CLD that is sufficient for an “accurate” prediction of equivalent fatigue loads and service lifetimes? To answer this question, the load data from two operating wind turbines and the failure of coupons tested using the WISPERX spectra are analyzed using a nonlinear damage model. For the analysis, the predicted service lifetimes that are based on the CLD constructed from 13 R-values are compared to the predictions for CLDs constructed with fewer R-values. The results illustrate the optimum number of R-values is 5 with them concentrated between R-values of −2 and 0.5, or −2 and 0.7.

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