铝合金电阻点焊压力信号的动态特征分析  

Dynamic characteristics analysis of resistance spot welding pressure signal of aluminum alloy

作　　者：陈树君[1] 郝键[1] 李方 邬娜[1] CHEN Shujun;HAO Jian;LI Fang;WU Na(Engineering Research Center of Advanced Manufacturing Technology for Automotive Components,Ministry of Education,Beijing University of Technology,Beijing,100124,China)

机构地区：[1]北京工业大学智能成形装备及系统研究所,汽车结构部件先进制造技术教育部工程研究中心,北京100124

出　　处：《焊接学报》2020年第3期1-6,I0001,共7页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51775007);北京市新世纪百千万人才工程资助项目(Q1001790201601);中国博士后科学基金资助项目(2017M610726).

摘　　要：基于点焊焊接过程信息采集系统,研究铝合金电阻点焊压力信号的动态特征.从时、频域角度对比分析飞溅焊点和正常焊点的压力信号,发现飞溅焊点压力信号会发生突变并具备明显的特征频率,而正常焊点无明显相关特征;采用db5小波对压力信号进行7层分解,获得不同频带下压力信号的时、频域波形及各层细节信号的能量比.结果表明,根据信号的不同形态和特征,提取通电阶段压力信号的标准差、小波分解细节信号目标层的峰-峰值、能量比的最高值以及其所在层数,均可作为识别飞溅缺陷的特征指标.Based on an information acquisition system,the dynamic characteristics of the pressure signal for resistance spot welding of aluminum alloy.The pressure signals of splashing spot and normal spot are compared and analyzed in time and frequency domains.It was found that there is a sudden change in the pressure signal of splashing spot with obvious characteristic frequency,while the normal spot has no such phenomenon;The db5 wavelet is used to decompose the pressure signal into seven levels to obtain the waveforms in time and frequency domains and the energy ratio of detail signals in different frequency bands.The results showed that according to different forms and characteristics of the pressure signal,the standard deviation of the pressure signal during the power phase,the peak-peak value in the target level,the highest value of the energy ratio and the number of level in the target layer of the wavelet decomposition detail signal can be extracted as the characteristic index to identify splashing spot.

关 键 词：铝合金点焊 压力信号 频域分析 小波分析 特征指标 

分 类 号：TG453[金属学及工艺—焊接]