Nonlinear multi-variate regression design of capacitor discharge welding of high strength steel nut

Based on orthogonal experiment,the property of welded joint by capacitor discharge welding between 22MnB5 high strength steel and M8 hexagonal flanged welding nut was investigated.The pullout force of welding nut was regarded as the main index to evaluate the joint quality.Meanwhile,the welding parameters,including electrode pressure,welding voltage,capacitance and interaction of each other,were considered as independent factors.Furthermore,a nonlinear regression model used to reveal the relationship between welding parameters and joint quality was established based on genetic algorithm.What’s more,the comparison between the regression model values and experiment values proved that all the relative error is less than 10% with a high accuracy.