基于修正热弹性应力分析的风机叶片热红外温度检测

Inspection of Wind Turbine Blades Based on Modified Thermoelastic Stress Analysis Using Thermal Detection of Infrared Radiation

随着海上风电的持续发展,风机的安全运维越来越重要。传统的停机检测方法代价较高,基于修正的热弹性应力分析(TSA),提出一种风机叶片热红外检测技术。经典TSA的应用条件是绝热(即高频率循环载荷),但风机叶片等结构承受的循环载荷达不到高频。为了提高热红外在低频率载荷下的检测精度,对经典TSA理论进行修正,并通过疲劳实验对修正模型进行验证。其次,利用BLADED风机仿真软件对叶片的推力进行分析,计算叶片3个方向的推力及推力变化频率。通过修正的TSA模型对低频率载荷下风机叶片的表面温度进行分析,进而通过TSA理论对叶片表面进行应力及损伤检测。

As power generated using offshore wind turbines continues to increase,maintaining safe operating conditions with respect to the wind turbines becomes increasingly important.The traditional downtime inspection method is costly.This study proposes a novel method for inspecting wind-turbine blades based on thermoelastic stress analysis(TSA)that employs thermal detection of infrared radiation.The necessary condition for TSA is to achieve adiabatic conditions(highfrequency cyclic loadings).However,wind-turbine blades are subjected to cyclic loadings that do not attain high frequencies.To improve the accuracy of the thermal detection of infrared radiation under low-frequency loadings,the classical TSA theory was modified and the correctness of the modified model was verified via fatigue tests.The BLADED wind turbine simulation software was used to analyze the blade thrust,and the thrust force and thrust variation frequency of the blade in the three directions were calculated.The surface temperatures of the wind-turbine blade under low-frequency loadings were analyzed using the modified TSA model.The proposed model can be used to detect stress and damage related to the blade surfaces.