Assessment of the locations of fatigue failure in a commercial vehicle cab using the virtual iteration method

Abstract

In this paper, fatigue damage analysis and structural improvement of a commercial vehicle cab were carried out, in which a simulation technique and durability road tests were combined. A full-scale finite element model of the cab was established and then validated by means of physical testing and analysis of its stiffness and its modal performance. The loading spectra, in accordance with the durability road test, were obtained by adopting the virtual iteration method. With the established finite element model, the stress distributions in the cab under unit excitation were determined. The obtained stress distributions were then used to assess the total fatigue life of the cab by employing the strain-life (e-N) method; thus, the critical regions were determined. The results showed that some components near the pillars and mounts are easy to damage because of the stress concentrations. It was also demonstrated that the predicted regions are reliable, which was verified by comparison with the physical durability road tests. Finally, structural improvements in the critical structures were made; the fatigue life assessment of the improved cab showed an obvious improvement in its durability performance. KeywordsAssessment of fatigue failure locations, finite element analysis, virtual iteration, commercial vehicle cab, structural improvement Date

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