Failure Analysis of Leaf Spring Used as the Rear Suspension System in Diesel Truck by Numerical and Fracture Mechanics Approach

Leaf springs are a type of spring designed to dampen vibrations caused by loading such as lateral loads, shock loads, and torsion. Due to the main role of this component makes its failure can directly cause a serious accident. This study aims to determine the cause of leaf spring failure in the 110 PS dump truck vehicle suspension system carried out by numerical and fracture mechanic approach. Numerically, leaf springs with initial defects were modeled using the finite element method software called FEMAP to find the value and the stress distribution that occurs in the leaf spring around the location of the initial defect. By fracture mechanics approaching, the stress results obtained are used to calculate the value of the stress intensity factor (KI) which is then compared with the value of crack toughness (KIC). Based on the results of stress simulation and calculation of stress intensity factor (KI), it was found that the stress that occurs is below the yield stress of the material and (KI) ≈ (KIC). From the results obtained, the study found that crack propagation was the cause of the leaf spring failure that occurred from the location of the initial defect. This failure occurs by the fatigue mechanism caused by repeated loading.