Abstract:In order to study the change of the fillet stress when the crankshaft is subjected to the bend-twist compounding load,a crankshaft of bend-twist compounding model is established and the accuracy of the model is verified by experiment.Under calibrated working conditions,the variation law of the maximum bend,twist,bend-twist compounding stress at transition fillet with the crankshaft angle was simulated.The maximum bend-twist compounding load was selected and the crankshaft quality was used as the constraint condition.The Workbench Design Exploration optimization module was used to optimize the response surface of the crankshaft for maximum stress and maximum deformation.The results show that within 0~180° Calibrated Angle(CA),with the increase of crankshaft angle,the fillet stress increases first and then decreases.The maximum fillet stress occurs 15°CA after (Top Dead Center)TDC.At the same time,the fillet stress is 4.9% larger than the maximum burst pressure moment and 26% larger than the fillet stress when the crankshaft at TDC.The transition fillet radius is the most sensitive to stress and deformation,and the sensitivity is -0.426 and -0.563.Through the response surface optimization analysis,the maximum stress of the crankshaft is reduced by 14.45% and the maximum deformation is reduced by 18.17% under the constraint condition.