Statistical approaches on the design of fatigue stress spectra for bus structures

Abstract

This paper presents technical procedures and statistical approaches on the extrapolation of fatigue stress spectra for the critical part of the bus structure. The approach for such stress spectra extrapolation can be used for determining long-term stress spectra at expected service life. Some extrapolation concepts are presented to show the suitable determination of the experimental data. The conventional Non-parametric and the simplified extreme value extrapolation approaches are utilised in the present case. The mathematical model is then used to verify the anticipated extreme stress level to some extrapolation factor, which is almost coincide. As a result, the extrapolated stress spectra histograms are compared with the evaluated fatigue damage and cycles counted based on several improved criteria. The extrapolated histograms appear to be reasonable results with higher stress amplitudes compared to the measured one and greatly contribute to the cumulative damage. This study results in satisfactory findings to the best of knowledge on the studied case. Thus, certain techniques and best practices are included in this article to be followed.