中文摘要：

通过试验掌握焊接过程中声发射信号特性是实现焊接裂纹声发射在线检测的前提。提出了一种基于谐波提取的声发射信号特性分析方法,结合焊接过程中声发射信号测试试验,对焊接过程中的声发射信号进行有效提取与频谱分析,获取了焊接过程中摩擦激励源、焊接电弧冲击激励源和焊接结构裂纹激励源声发射信号的频域特性。为实现焊接过程中的结构裂纹声发射在线检测提供了基础数据及参考依据。

英文摘要：

Characteristic analysis of the acoustic emission（AE）signal accompanying welding process by way of experiment is a prerequisite for realizing online detection of the welding crack.An AE signal characteristic analysis method based on harmonic extraction is proposed.Combining with an experiment on AE signals during the welding process,the valid extraction and frequency spectrum analysis are performed for AE signals collected in welding process.The AE signals frequency domain characteristics of the corresponding excitation source of friction,the welding arc shock and the welding structure crack are obtained respectively,which provide basic data and reference for realizing AE online detection of the welding crack.