作者：张鹏林1,2, 杨超2, 董拴涛2, 田宁2
作者单位：1. 兰州理工大学 省部共建有色金属先进加工与再利用国家重点实验室, 甘肃 兰州 730050;
2. 兰州理工大学材料科学与工程学院, 甘肃 兰州 730050
关键词：风电叶片;CEEMD;Lamb波;声发射源定位
摘要：
声发射波在风电叶片薄板结构中传播时产生的多模态效应及频散现象使得波速的测定较为困难，导致声发射源定位误差过大。针对以上问题，从声发射波传播的物理机制出发，利用完备总体经验模态分解（CEEMD）结合Lamb波理论对风电叶片复合材料在不同应力状态下产生的声发射波进行断铅实验研究。研究结果表明：作用于叶片薄板结构的应力方向不同，将会产生不同频率、不同声速的应力波。垂直应力主要激发出弯曲波，该波波速较低（约1 357 m/s），幅值衰减较快，频率主要集中于50 kHz左右；平行应力主要激发出扩展波，该波波速较高（约3 634 m/s），幅值衰减较慢，频率主要集中于150 kHz左右。扩展波无频散效应且衰减较慢，更加适合风电叶片薄板结构声发射源定位。
Research on localization of acoustic emission source in composite of wind turbine blade based on the Lamb wave
ZHANG Penglin1,2, YANG Chao2, DONG Shuantao2, TIAN Ning2
1. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China;
2. School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
Abstract: The veracity of the velocity is the key to locate the position of a fault using the acoustic emission technology in the Time Difference of Arrival (TDOA). However, the frequency dispersion and modes generated from the propagation of the wave in a thin plate make it hard to acquire the wave speed accurately. Based on the physical mechanism of the propagation of Lamb wave, the combination of complementary ensemble empirical mode decomposition (CEEMD) is used combined with the theory of Lamb wave to analyze the signal under various excitations for locating the correctness of the acoustic emission source in the wind turbine blade by leading crack. The result shows that the kind of wave plays a main role in the plate when the force is parallel to the plate; another wave has the same role in the plate when the force is perpendicular to the plate, respectively. There is a higher velocity at 3634 m/s, high frequency about 150 kHz for the former, compared to the wave of lower frequency, and the later has the lower velocity about 1357 m/s, frequency on 50 kHz. It is proved that using the former, with a lower attenuation and for amplitude, and without frequency dispersion to calculate acoustic emission source is better for wind turbine blade.
Keywords: wind turbine blade;CEEMD;Lamb wave;location for acoustic emission source
2019, 45(7):140-146 收稿日期: 2017-11-12;收到修改稿日期: 2018-01-03
基金项目:
作者简介: 张鹏林(1973-),男,甘肃白银市人,副研究员,博士,主要从事无损检测、无损评估等方面的研究
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