关键词: 电阻点焊, 级联森林, SHAP值, 差分进化

Abstract: Resistance spot welding (RSW) of heterogeneous materials is a complex nonlinear physical process,and it is difficult to establish a mathematical mapping model between welding process parameters and nugget diameter.The adaptive evolution algorithm was used to predict nugget diameter by combining with cascade forest.Considering the characteristics of the experimental data of Resistance Spot Welding (RSW) of two-layer unequal thickness heterogeneous plates,the material information was characterized by physical property and chemical composition of the material.The process and material were selected as the quality influencing factors to be the model's input features.Random forest,XGBoost and Light GBM were cascaded into the traditional cascade forest as meta-learners respectively,and the adaptive differential evolution algorithm was applied to the cascade forest's optimal parameters selection.The SHAP theory was introduced to analyze the impact of input features on the nugget diameter.The experimental results showed that the R2、MSE of the cascade forest model optimized by hyperparameters on the test set were 0.9480 and 0.0315 respectively,which were better than the baseline model.The important influencing factors of the nugget diameter were determined,which provided a basis for the design of process parameters for welding of new materials.

Key words: resistance spot welding, cascade forest, SHAP value, differential evolution