Deterministic and probabilistic fatigue life calculations of a damaged welded joint in the construction of the trolleybus rear axle

In trolleybuses in service, fatigue cracks were frequently encountered in a welded structural detail in their rear axle housing. Sufficiently representative stress-time histories for the critical cross section through this part were obtained by measurement during rides with empty as well as fully-loaded vehicles. The fatigue characteristics of the critical location had to be established by estimation. This information was used as the basis for parametric calculations of fatigue life. The main purpose of these calculations was to ascertain whether these in-service failures could have been predicted (and prevented) during the design stage, and what their main cause had been. Furthermore, this investigation explored the feasibility of verifying this structural detail's service life using the fatigue life distribution function. The paper is expanded work published at the 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal [1].