Fatigue Life Improvement of engine mounting bracket using cumulative fatigue test and numerical modeling

Engine mount bracket is one of the important parts of the car that produced by die-casting method. Failure of engine mount bracket can create irreparable risks. In the operating condition of the vehicle, the engine mount bracket is subjected to oscillatory loading, and manufacturing process such defects caused by uncontrolled casting parameters and its geometrical shape can effect on component fatigue life. In this study, the fatigue life of engine mount bracket was evaluated experimentally. Fatigue strength of specimen is derived that is 1.24 times bigger than critical strength with high dispersion using the Locati-Stair Case method that shows this component in unsafe status. Therefore, finite element simulation was performed to determine the critical areas and improve the geometric shape. The locations of crack initiation were similar in fatigue test and finite element simulation. After improving the geometric shape of engine mount bracket, experimental tests were performed again. The results showed an improvement of fatigue strength up to 1.33 times with lower dispersion that shows component is in safe status.