电阻点焊位移信号的混沌与分形特性试验  

Chaos and Fractal Characteristics of Electrode Displacement Signals in the Spot Welding

作　　者：罗震[1] 王蕤[1] 单平[1] 马迎兵[1] 邹帆[1] 

机构地区：[1]天津大学材料科学与工程学院,天津300072

出　　处：《机械工程学报》2008年第6期143-147,共5页Journal of Mechanical Engineering

基　　金：国家自然科学基金(50575159);教育部基金(106049;20060055058);天津市应用基础研究计划基金(06YTJMJC03400)资助项目

摘　　要：以混沌理论为基础对电阻点焊位移信号进行分析与研究,通过对7种不同工作状态下时间序列的最大Lyapunov指数计算,发现点焊位移信号的值均大于0,证明位移信号中存在混沌现象,应采用混沌的方法研究与分析点焊位移信号,该研究为点焊质量的判断和预测开辟有效的途径。由于用经典欧式几何方法描述位移信号误差较大,提出用分形维数作为特征值来量化具有混沌特性的点焊质量,点焊位移检测试验结果表明此方法能反映点焊质量微小变化,可提高质量检验的准确性。Based on chaos time series and fractal theory, electrode displacement signals are studied in the process of spot welding. Seven states of electrode displacement signals are studied to determine the largest Lyapunov exponents from acquired time series data. According to the calculating results using phase space reconstruction, the largest Lyapunov exponents are positive number in the seven states of electrode displacement signals, and chaos characteristics are discovered in electrode displacement signals of spot welding. Therefore, the result shows a new state in the process of the spot welding and electrode displacement signals should be analysed by chaos method. In order to research electrode displacement signal, box counting dimension is put forward to analyze and calculate chaos characteristics. The experiment and calculation results indicate that the box counting dimension of electrode displacement signals is clearly distinguishable in the welding process with different welding parameters. A new method of judging and forecasting the quality of spot welding is provided.

关 键 词：点焊 电极位移信号 LYAPUNOV指数 混沌时间序列 分形维数 

分 类 号：TG453[金属学及工艺—焊接]