Optimization Design and Fracture Analysis of 60Si2Mn Steel Front Stabilizer Bar for Automobile

A 60Si2Mn steel front stabilizer bar for automobile suffered fatigue fracture during bench endurance test. The fracture reasons were analyzed macroscopic morphology observation, chemical composition analysis, hardness test and metallographic inspection. Two optimization schemes were proposed, and stress analysis, fatigue life test, bench endurance test, subjective driving evaluation and road reliability test were carried out on the optimized front stabilizer bar. The results show that the reverse change of the shape between the left and right limit rings caused line stiffness increasing of the front stabilizer bar, and fatigue fracture occurred under the action of alternating stress. Changing the material to 55Gr3 steel and reducing the diameter and bore diameter to 21, 20.5 mm could effectively reduce the linear stiffness and roll stiffness of front stabilizer bar. After optimization, the stress distribution, fatigue life, subjective driving evaluation, bench endurance and road reliability test of the front stabilizer bar all met the requirements.