Fatigue Analysis of Vehicle Chassis for Three-Axle Truck Using Ansys Software

The fatigue performance of a three-axle truck chassis is an important consideration for ensuring structural reliability under variable road-induced loading. This study presents a numerical investigation of the fatigue behavior of a three-axle truck chassis using finite element analysis in ANSYS. A three-dimensional chassis model was developed in SolidWorks and evaluated under static loading, modal analysis, and dynamic road excitation corresponding to ISO 8608 Class D and Class E road profiles at a vehicle speed of 20 km/h. The fatigue life and fatigue damage were predicted using the Goodman, Gerber, and Soderberg mean-stress correction criteria under identical material and loading conditions. The static analysis identified the rear suspension mounting region as the critical structural area, with a maximum von Mises stress of 382.39 MPa, while the minimum predicted fatigue lives under Class D were 8338.5, 8290.4, and 8338.5 cycles for the Goodman, Gerber, and Soderberg criteria, respectively. Under the more severe Class E road profile, the corresponding minimum predicted fatigue lives were 6349.9, 6306.2, and 6349.9 cycles, indicating that road excitation severity has a greater influence on the predicted fatigue life than the selection of the mean-stress correction criterion under the present loading conditions.