Structural Optimization for Stiffness and Stochastic Fatigue Life Improvement of a Sport Utility Vehicle Chassis

To further improve the structural dynamic performance of the Land-Wind X-6 chassis, structural optimization was performed: An X-shape cross member with high stiffness is added to the chassis, in addition, the cross member connecting the two torsion bar attachments is also strengthened. Extensive Finite Element Analysis (FEA) demonstrates that the inadequate torsion stiffness has been greatly increased by 102.6% after optimization, and the adequate bending stiffness has also been slightly improved by 3.8%, in addition, the level of local stresses on the chassis has been considerably declined; After optimization, the fatigue life coefficient when the vehicle is running on A-class concrete road at a speed of 110 km/h has been improved by about 40.36%, and that when the vehicle is running on D-class macadam road at a speed of 60 km/h has been improved by about 33.43%. Followed industrial implementation, field test result and product feedback information verify that the structural optimization performed in this study is effective and significant.