| 基于声发射技术模拟蛀木害虫羽化孔洞缺陷检测 |
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| 引用本文： | 豆春峰,李明,朱代根.基于声发射技术模拟蛀木害虫羽化孔洞缺陷检测[J].中南林业科技大学学报,2021(2). |
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| 作者姓名： | 豆春峰 李明 朱代根 |
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| 作者单位： | 西南林业大学机械与交通学院 |
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| 基金项目： | 国家自然科学基金项目“基于声发射能量模型的胶合木结构蠕变机理与演变规律”(31760182)。 |
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| 摘 要： | 【目的】针对木材蛀干害虫羽化孔洞缺陷检测问题,通过对声发射信号的时频分析,研究木材蛀干害虫羽化孔洞缺陷的AE信号特征。【方法】首先,对无孔洞和3种不同尺寸的钻孔缺陷的木材试件,参照ASTM-E976标准采用铅芯折断方式产生AE源,通过采样频率为500 kHz的2通道木材声发射信号采集系统获取原始AE信号。然后,对原始AE信号进行降噪滤波,再对滤波后的信号进行小波分解并重构AE波形,分析孔径对AE信号频率分布的影响。最后,采用信号相关性分析法和时差定位法,计算AE信号的传播速率,进而分析羽化孔径对传播速率的影响。【结果】AE信号通过无孔洞、5 mm孔洞、8 mm孔洞、15 mm孔洞缺陷,AE信号的主频率分别为38、43、51、117 kHz,AE信号传播的平均速率分别为1 380.7、1 067.3、848.6、437.1 m/s。【结论】AE信号在不同孔径缺陷的木材试件传播时,随着孔洞缺陷的增大,AE信号的幅值发生明显衰减,AE信号的主频率增大,AE信号传播的平均速率减小。为了验证试验结果和结论,找了具有天然蛀干害虫羽化孔洞缺陷的木材试件,孔洞直径约为20 mm,使用相同的方法采集和处理AE信号,AE信号通过天然蛀干害虫羽化孔洞缺陷的主频率为121 kHz,AE信号传播的平均速率为324 m/s。
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| 关 键 词： | 声发射 蛀干害虫 羽化孔洞 小波分解 相关性分析 |
The detection of hole defects in the simulation of wood borer based on acoustic emission technology |
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| DOU Chunfeng,LI Ming,ZHU Daigen.The detection of hole defects in the simulation of wood borer based on acoustic emission technology[J].Journal of Central South Forestry University,2021(2). |
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| Authors: | DOU Chunfeng LI Ming ZHU Daigen |
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| Institution: | (College of Machinery and Transportation,Southwest Forestry University,Kunming 650224,Yunnan,China) |
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| Abstract: | 【Objective】Based on the time-frequency analysis of acoustic emission(AE)signal,the AE signal characteristics of the emergence hole defects of wood borers are studied.【Method】Firstly,for the wood samples without holes and three kinds of holes with different sizes,the AE source is generated by the way of lead core breaking according to astm-e976 standard,and the original AE signal is obtained by the two-channel wood acoustic emission signal acquisition system with sampling frequency of 500KHz.Then,the original AE signal is denoised and filtered,then the filtered signal is decomposed by wavelet and reconstructed AE waveform,and the influence of aperture on AE signal frequency distribution is analyzed.Finally,the propagation rate of AE signal is calculated by signal correlation analysis and time difference location,and then the influence of feathered aperture on the propagation rate is analyzed.【Result】AE signals pass through holes,5 mm holes,8 mm holes,and 15 mm holes.The main frequencies of the AE signals are 38 kHz,43 kHz,51 kHz,and 117 kHz.The average speed of AE signal propagation were 1380.7 m/s,1067.3 m/s,848.6 m/s,and 437.1 m/s.【Conclusion】When AE signal propagates in wood samples with different pore size defects,with the increase of pore size defects,the amplitude of AE signal attenuates obviously,the main frequency of AE signal increases,and the average speed of AE signal propagation decreases.In order to verify the test results and conclusions,the wood samples with the hole defect of natural stem borer were found.The hole diameter was about 20 mm.The AE signal was collected and processed by the same method.The main frequency of AE signal passing through the hole defect of natural stem borer was 121 kHz,and the average speed of AE signal propagation was 324 m/s. |
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| Keywords: | Acoustic emission dry pests feathered holes wavelet decomposition correlation analysis |
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