Reliability-based gear contact fatigue analysis for wind turbines under stochastic dynamic conditions

2014 ◽  
pp. 5571-5578
Author(s):  
W Dong ◽  
T Moan ◽  
Z Gao
Keyword(s):  
Wind Turbines ◽  
Contact Fatigue ◽  
Fatigue Analysis ◽  
Stochastic Dynamic ◽  
Dynamic Conditions ◽  
Gear Contact

scholarly journals Gear Contact Fatigue Reliability Analysis for Wind Turbines Under Stochastic Dynamic Conditions Considering Inspection and Repair

2014 ◽  
Author(s):  
WenBin Dong ◽  
Torgeir Moan ◽  
Zhen Gao
Keyword(s):  
Time Series ◽  
Wind Turbine ◽  
Reliability Analysis ◽  
Wind Turbines ◽  
Contact Fatigue ◽  
Crack Size ◽  
Contact Forces ◽  
Stochastic Dynamic ◽  
Fatigue Reliability ◽  
Gear Contact

Reliability is one of the most important features of the wind turbine gearbox, especially in offshore wind turbines (OWTs). This paper describes a general way to perform gear contact fatigue reliability analysis for wind turbines considering inspection and repair. A simplified predictive surface pitting model for estimating gear fatigue lives is applied to establish the ‘so-called’ limit stated functions. The National Renewable Energy Laboratory (NREL)’s 750kW land-based wind turbine is used to perform time domain simulations considering different wind speeds that the turbine will experience, whose occurrence frequencies are described by a generalized gamma distribution. The time series of the torques in the main shaft are obtained from the global dynamic response analysis of the wind turbine. The time series of the gear contact forces are obtained from the dynamic analysis of the gearbox through multi-body simulation. The 2-parameter Weibull distribution is used to fit the long-term probability distribution of the gear tooth contact pressures. The reliability analysis is based on fracture mechanics (FM) analysis of crack growth. Finally the sensitivity of the reliability index and failure probability on initial crack size, critical crack size, detectable crack size, crack size after repair, material property and environmental loads is estimated considering the effect of inspection.

scholarly journals Development of a Granular Cohesive Model for Rolling Contact Fatigue Analysis: Crystal Anisotropy Modeling

2016 ◽  
Vol 59 (3) ◽  
pp. 469-479 ◽  
Author(s):  
J.-P. Noyel ◽  
F. Ville ◽  
P. Jacquet ◽  
A. Gravouil ◽  
C. Changenet
Keyword(s):  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Fatigue Analysis ◽  
Rolling Contact ◽  
Cohesive Model ◽  
Crystal Anisotropy

Research on Gear Contact Fatigue Stress Test

2011 ◽  
Vol 86 ◽  
pp. 825-828
Author(s):  
Tie Wang ◽  
Hong Mei Li ◽  
Rui Liang Zhang ◽  
Zhi Fei Wu
Keyword(s):  
Damage Accumulation ◽  
Stress Test ◽  
Contact Fatigue ◽  
Test Method ◽  
Fatigue Stress ◽  
Accumulation Curve ◽  
Limit Value ◽  
Fatigue Damage Accumulation ◽  
Gear Contact ◽  
The Cost

This paper put forward the rapid measure method of the gear contact fatigue stress value with a few gear samples, which can get the estimated value of the gear fatigue limit value precisely and rapidly. And the gear fatigue life curve and fatigue damage accumulation curve are simulated by MATLAB. Comparing with the traditional test method, this method can reduce the cost and save the time.

Numerical Prototyping of Floating Offshore Wind Turbines: Virtual Operation in Real Environmental Conditions

2020 ◽  
Author(s):  
Daniel Milano ◽  
Christophe Peyrard ◽  
Matteo Capaldo
Keyword(s):  
Wind Turbines ◽  
Wind Wave ◽  
Fatigue Analysis ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wave Direction ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Wave Conditions

Abstract The numerical fatigue analysis of floating offshore wind turbines (FOWTs) must account for the environmental loading over a typical design life of 25 years, and the stochastic nature of wind and waves is represented by design load cases (DLCs). In this statistical approach, combinations of wind speeds and directions are associated with different sea states, commonly defined via simplified wave spectra (Pierson-Moskowitz, JONSWAP), and their probability of occurrence is identified based on past observations. However, little is known about the difference between discretizing the wind/wave direction bins into (e.g.) 10deg bins rather than 30deg bins, and the impact it has on FOWT analyses. In addition, there is an interest in identifying the parameters that best represent real sea states (significant wave height, peak period) and wind fields (profile, turbulence) in lumped load cases. In this context, the aim of this work is to better understand the uncertainties associated to wind/wave direction bin size and to the use of metocean parameters as opposed to real wind and sea state conditions. A computational model was developed in order to couple offshore wind turbine models with realistic numerical metocean models, referred to as numerical prototype due to the highly realistic wind/wave conditions in which it operates. This method allows the virtual installation of FOWTs anywhere within a considered spatial domain (e.g. the Mediterranean Sea or the North Sea) and their behaviour to be evaluated in measured wind and modelled wave conditions. The work presented in this paper compares the long-term dynamic behaviour of a tension-leg platform (TLP) FOWT design subject to the numerical prototype and to lumped load cases with different direction bin sizes. Different approaches to representing the wind filed are also investigated, and the modelling choices that have the greatest impact on the fidelity of lumped load cases are identified. The fatigue analysis suggests that 30deg direction bins are sufficient to reliably represent long-term wind/wave conditions, while the use of a constant surface roughness length (as suggested by the IEC standards) seems to significantly overestimate the cumulated damage on the tower of the FOWT.

An Approach for the Gear Rolling Contact Fatigue Acceleration

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Sheng Li ◽  
Jeremy J. Wagner
Keyword(s):  
Film Thickness ◽  
Crack Formation ◽  
Crack Nucleation ◽  
Rotational Velocity ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Time Period ◽  
Gear Contact ◽  
Gear Rolling

This study proposes an approach for the acceleration of the experimental gear rolling contact fatigue (RCF) crack formation. By increasing the rotational velocity of a gear pair, the RCF experimental time period is reduced. However, the film thickness is increased to improve the fatigue performance, to counteract which it is proposed to raise the lubricant temperature to reduce the film thickness. A physics-based gear contact fatigue model is used to quantify and offset the effects of the rotational velocity and the lubricant temperature on the crack nucleation.

scholarly journals Fatigue Analysis of Copper Conductor for Offshore Wind Turbines by Experimental and FE Method

2012 ◽  
Vol 24 ◽  
pp. 271-280 ◽  
Author(s):  
Fachri P. Nasution ◽  
Svein Sævik ◽  
Janne.K.Ø. Gjøsteen
Keyword(s):  
Wind Turbines ◽  
Fatigue Analysis ◽  
Offshore Wind ◽  
Fe Method ◽  
Offshore Wind Turbines ◽  
Copper Conductor
Sign in / Sign up

Export Citation Format

Share Document