金属拉伸声发射信号特征分析  

The feature analysis for acoustic emission signal of metal strength

作　　者：伍蒋军 黄振峰 毛汉领 

机构地区：[1]浙江省特种设备检验研究院,浙江杭州310021

出　　处：《浙江工业大学学报》2011年第3期301-303,322,共4页Journal of Zhejiang University of Technology

基　　金：国家自然科学基金资助项目(50465002);广西省自然科学基金资助项目(桂科基0448014)

摘　　要：在利用声发射技术对金属缺陷的萌生、扩展及断裂过程进行检测时,必须明确缺陷产生不同阶段的声发射信号特征.为了获取该特征,采用金属拉伸试验模拟金属缺陷产生过程.为此,利用现有DSP数据采集系统搭建金属拉伸试验平台,根据GB 228-2002《金属材料试样拉伸实验方法》,进行拉伸试验.经分析,试验所得不同阶段声发射信号时域特征与理论吻合;再利用不同阶段典型声发射事件进行频域分析,发现频率成分明显不同,塑性变形和屈服阶段频率成分主要集中于低频段,断裂阶段频率成分在高频段显著增加.金属拉伸过程不同阶段声发射信号的时域、频域特征差别明显.When the acoustic emission（AE） technique is used to detect the process of metal defect initiation,expansion and fracture,the feature of acoustic emission signal must be clear at different stages of defect.In order to get the feature of AE signal,the metal strength test was used to simulate the process of metal defect.Therefore the existing DSP data acquisition system was used to build the metal strength test platform and the test was done according to the GB 228—2002《Metal material tensile test method of specimen》.The analysis certified that the time domain feature of AE signal is consistent with the theory,then the typical AE event of different stages was used to do frequency domain analysis.It was found that frequency components was distinctive where the frequencies of deformation and yield stage focused on low frequency and the high frequency increased in fracture stage.The difference of AE time domain and frequency feature was conspicuous in the different stages of metal strength test.

关 键 词：声发射 金属缺陷 金属拉伸 时域特征 频域特征 

分 类 号：TN911[电子电信—通信与信息系统]