基于动态电阻理论分析与试验的点焊质量预测模型建立

Establishing of Spot Welding Quality Prediction Model Based on Theoretical Analysis of Dynamic Resistance and Experiment

以点焊动态电阻变化特征曲线为基础,根据熔合区焊接能量的变化,从理论上分析了熔核直径与焊接时间的关系,并得出两者的数学模型。以DP600双相钢为试验材料,采用工频交流点焊中的恒流控制法,根据K_n值选取焊接电流及焊接时间等工艺参数进行试验,并测得最终熔核直径。以建立的数学模型为基础拟合了试验数据,拟合结果最大误差为0.224 mm,并从理论上解释了数学模型中的系数与焊接参数的关系。

Based on the dynamic resistance curve of spot welding and the change of energy in the fusion zone, the mathematical model and relationship between the fusion diameter and welding time were obtained by theoretically analysis.Then the fitted curves based on above model were acquired with the nugget diameter of the experiment, which was conducted on the power frequency AC resistance spot welding equipment with DP600 dual phase steel as experimental material. The experiment parameters were selected by the means of K_n, which was illustrated in the passage. According to the results of the fitted curves, the biggest error was 0.224 mm. And the relationship between the coefficients of the model and welding parameters was explained theoretically at last.