摘要
针对断铅声发射实验信号应用广泛而又没有深入分析的现状,为了更深层次地揭示断铅声发射实验信号的特点,探究了不同分析方法下断铅声发射信号的差异。分别采用了经验模态分解和5层小波变换方法,将断铅声发射实验信号进行了分解重构,并对分解重构信号的时域和频域特征进行了剖析;经验模态分解采用相关系数法,得到了6个固有模态函数,对声发射信号进行了深入分析。研究结果表明:经验模态分解与小波变换能够将断铅信号的低频噪音信号分离出来,可准确提取铅芯断裂声发射特征信息;同时结合断铅声发射信号的短时傅里叶变换分析也发现了噪声分布在相近的频率范围内,进一步说明了经验模态分解与小波变换分离断铅信号中低频噪音信号的准确性。
Aiming at the present situation of wide application and no in-depth analysis of the acoustic emission experimental signal of pencillead breaking,in order to reveal the characteristics of pencil-lead break acoustic emission（ AE） signal in a deeper level and to explore the difference of pencil-lead break AE signal under different analysis methods,empirical mode decomposition（ EMD） and 5-layer discrete wavelet transform（ DWT） were respectively used to decompose and reconstruct pencil-lead break AE signals. The time-domain and frequency-domain features of the decomposed and reconstructed AE signals were analysed. In the EMD 6 intrinsic modal functions were obtained by using the correlation coefficient method to analyse the AE signal in depth. The results indicate that low frequency noise in the AE signal is filtered and the lead fracture characteristic information can be accurately extracted by EMD and DWT. At the same time,the analysis of pencil-lead break AE by short-time Fourier transform also find that the noise is distributed in the similar frequency range,which further proves the accuracy of the low frequency noise filtered in the AE signal filtered. EMD and 5-layer wavelet transform are used to decompose and reconstruct pencil-lead break AE signal and the low frequency noise signalin the AE signal is filtered out,which can extract the lead fracture characteristic information. At the same time,the analysis of pencil-lead break AE by short-time Fourier transform also proves its accuracy.
作者
郭力
霍可可
GUO Li;HUO Ke-ke(College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China)
出处
《机电工程》
CAS
北大核心
2018年第7期663-667,684,共6页
Journal of Mechanical & Electrical Engineering
基金
国家自然科学基金资助项目(51475157)
关键词
声发射
断铅
小波变换
经验模态分解
短时傅里叶变换
acoustic emission
pencil-lead break
wavelet analysis
empirical mode decomposition（EMD）
short time Fourier transform
