Welded portion characteristic prediction method, prediction model generation method, and prediction model

A prediction model generation method of generating a model to predict characteristics of a welded portion of a sheet combination of two or more overlapping metal sheets, the welded portion being obtained by resistance spot welding to pass a current between two electrodes clamping the sheet combination of two or more overlapping metal sheets, the method comprising:

• acquiring electrical information outputted during resistance spot welding, the electrical information including at least one of the current flowing between the two electrodes, a voltage between the two electrodes, a resistance between the two electrodes, and an amount of heat generated between the two electrodes during the resistance spot welding;
• acquiring an analysis result of characteristics of the welded portion when resistance spot welding is performed on the sheet combination of two or more overlapping metal sheets;
• and
• generating a model to predict the characteristics of the welded portion of the sheet combination of two or more overlapping metal sheets by performing machine learning based on learning data associating the electrical information with the analysis result of the characteristics of the welded portion when resistance spot welding is performed on the sheet combination of two or more overlapping metal sheets.