风力机叶片裂纹的动态扩展特性研究  

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

作　　者：周勃[1] 陈长征[1] 张宇[1] 孟强[1] 

机构地区：[1]沈阳工业大学辽宁省振动噪声控制技术工程研究中心,沈阳110870

出　　处：《中国机械工程》2013年第8期1108-1113,共6页China Mechanical Engineering

基　　金：国家自然科学基金资助项目(51005159;50975180);辽宁省教育厅基金资助项目(L2010401)

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。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 ex- traction 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 meth- od can provide the theoretic foundation for condition monitoring and early warning of wind turbine blade.

关 键 词：风力机 叶片 扩展裂纹 声发射信号 

分 类 号：TK83[动力工程及工程热物理—流体机械及工程] TH165[机械工程—机械制造及自动化]