基于声发射技术的Q345焊接接头特征信号分析

Q345 Welded Joint Characteristic Signal Analysis Based on Acoustic Emission Technology

以Q345为研究对象,基于声发射技术对正常焊接接头和预制缺陷焊接接头的拉伸加载过程进行了动态监测,获得了加载过程中的特征声发射信号,并通过傅里叶变换对信号进行了频谱分析。分析结果表明:信号的撞击计数、能量和幅值与时间之间基本符合线性关系,能够较好地表征试件拉伸过程的各个阶段;预制缺陷引起应力集中,屈服阶段和强化阶段能量与幅值比较突出;Q345试样的拉伸频率主要集中在100kHz^300kHz。

Tensile loading processes of Q345 welded joints with and without prefabricated defects were dynamically monitored on the basis of acoustic emission technology.The characteristic acoustic emission signal generated during the loading processes were recorded and then analyzed by Fourier transformation.Results show that the impact count,energy and amplitude are perfectly consistent with the loading time,which could accurately describe every stage of the tensile loading processes of the sample;the energy and amplitude of the yield stage and the strengthening stage are more prominent because of the stress concentration caused by bar slag defect;spectrum analysis indicates that the tensile frequency of Q345 welded joints are located in the range of 100kHz-300 kHz.