基于超声信号增益补偿的电阻点焊熔核直径评估算法  

Resistance spot welding nugget diameter estimation algorithm based on ultrasonic signal gain compensation

作　　者：吴刚 关山月 汪小凯[2,3] 王彬 WU Gang;GUAN Shanyue;WANG Xiaokai;WANG Bin(College of Mechanical and Power Engineering,China Three Gorges University,Yichang 443002,China;Hubei Key Laboratory of Modern Automotive Technology,Wuhan University of Technology,Wuhan 430070,China;Hubei Collaborative Innovation Center for Automotive Components and Technology,Wuhan 430070,China)

机构地区：[1]三峡大学机械与动力学院,湖北宜昌443002 [2]武汉理工大学现代汽车零部件技术湖北省重点实验室,湖北武汉430070 [3]汽车零部件技术湖北省协同创新中心,湖北武汉430070

出　　处：《中国测试》2018年第8期13-19,共7页China Measurement & Test

摘　　要：该文针对电阻点焊超声检测熔核直径评估算法中,检测信号各波峰幅值不同程度衰减对熔核直径评估结果的影响,提出一种基于小波变换超声信号增益补偿方法,将原信号进行3层小波分解获得4个子带信号,分别计算各子带信号衰减系数并补偿,再通过小波重构得到重构信号,最后利用重构信号计算熔核直径。通过构建点焊超声检测有限元仿真模型,研究信号衰减对熔核直径计算结果的影响,为试验提供理论依据。运用该方法处理多组点焊超声检测数据,对比分析处理前后熔核直径计算值与金相实测值,研究结果表明,采用该方法处理超声信号并计算点焊熔核直径,误差减小到0.1 mm,可有效提高评估精度。In this paper,a method of ultrasonic signal gain compensation based on wavelet transformation is proposed,considering the influence of different attenuation degrees of all waves of test signals on the evaluation results of nugget diameter in the valuation algorithm for nugget diameter of resistance spot-welding.In this method,the original signal is decomposed by three layers to obtain four sub-band signals.The signal attenuation coefficient of each sub-band is calculated and compensated,and the reconstructed signal is obtained by wavelet reconstruction.Finally,the reconstructed signal is used to calculate the nugget diameter.The finite element simulation model of ultrasonic testing for spot welding was constructed to study the effect of signal attenuation on the calculation results of nugget diameter,providing a theoretical basis for the experiment.This method is applied to deal with multiple groups of spot welding ultrasonic testing data and provide a contrastive analysis of the calculated nugget diameter and metallographic measured value.The results show that the error can be reduced to 0.1 mm by using this method to process ultrasonic signals and calculate the nugget diameter of spot welding,which improves the evaluation accuracy.

关 键 词：电阻点焊 超声检测 增益补偿 熔核直径 

分 类 号：TG453.9[金属学及工艺—焊接]