Research on Dynamic Propagating Characteristics of Wind Turbine Blade's Cracks

Abstract

Abstract:

Firstly,the stress intensity factor was derived for the crack tip in
the plastic zone of wind turbine blade to determine the main factors affecting the crack
propagation.And the feature extraction method of AE signals was
discussed according to the AE characteristics of crack propagation.
During the test,the specimen characteristics were analyzed and the different wavelet basis
functions were compared to ascertain the impact on feature extraction for the AE signals collected from the propagating crack.
Finally,the characteristic frequency of dynamic propagating crack was extracted and
the mechanism of the association between the characteristic parameters and AE
source.The method can provide the theoretic foundation for condition monitoring and early warning of wind turbine blade.

Key words: wind turbine, blade, crack growth, acoustic emission(AE) signal

摘要：

首先推导了风力机叶片裂纹尖端塑性区的应力强度因子，确定了影响裂纹扩展的主要因素，然后根据裂纹扩展时的声发射信号特性，探讨了声发射信号的特征提取方法。在试验中分析了不同试件的裂纹形貌特性，并针对采集的裂纹扩展声发射信号，比较了不同小波基函数对声发射信号特征提取的影响，提取了裂纹动态扩展的特征频率，从而建立了声发射特征参数与声发射源之间的关联机制，为风力机叶片状态监测和早期预警提供理论依据。

关键词: 风力机, 叶片, 扩展裂纹, 声发射信号

CLC Number:

TK83
TH165

ZHOU Bo, CHEN Chang-Zheng, ZHANG Yu, MENG Jiang. Research on Dynamic Propagating Characteristics of Wind Turbine Blade's Cracks[J]. China Mechanical Engineering, 2013, 24(08): 1108-1113.

周勃, 陈长征, 张宇, 孟强. 风力机叶片裂纹的动态扩展特性研究[J]. 中国机械工程, 2013, 24(08): 1108-1113.

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