Failure analysis of transmission group shafts at working with variable load

In this study, failure analysis of the transmission input shaft for heavy duty trucks is made. Characteristics on fracture surface of damaged transmission input shaft can provide information on the damage type of material. As a result of the investigation on the damaged shaft, the algorithm has been created. Fatigue under variable loads connected to the brittle fracture was determined and the equivalent stress, equivalent fatigue stress and fracture analysis was performed. The unsafe critical point where nucleation of damage is grease nipples on shaft that were analyzed with finite element method. Metallurgical and constructions improvements on transmission input shaft are performing a structure improved resistance against fatigue was prepared.