Fatigue Analysis of Nonstationary Random Loadings Measured in an Industrial Vehicle Wheel: Uncertainty of Fatigue Damage

Abstract

This article presents an application of a method for estimating the inherent statistical variability of the fatigue damage computed in one single nonstationary random time history. The method applies the concept of confidence interval for the damage, which is constructed after the single time history is subdivided into pseudo-stationary segments, with each of them further divided into shorter blocks. As a case study, the method is applied to the strain time histories measured in a wheel of a telescopic handler industrial vehicle. A preliminary screening involving the short-time Fourier transform and the run test is carried out to verify whether the measured time histories are truly nonstationary and fall within the hypotheses of the proposed method. After that, the confidence interval for the unknown expected damage is computed; its upper bound can be used as a safety limit in a structural integrity assessment. The obtained results seem very promising and suggest the possible use of the proposed approach in similar engineering applications.

The use of fractional order statistics for estimating nonparametric confidence intervals for quantiles of the fatigue damage computed in service random loadings

“…Methods for identifying different states in z(t) (fast Fourier transform, run test) are described in [14]. After state identification, each state is further subdivided into N B blocks of equal length T B .…”

Fracture, Fatigue, and Structural Integrity of Metallic Materials and Components Undergoing Random or Variable Amplitude Loadings

“…The topic of structural integrity assessment of engineering components is discussed in four papers [7][8][9][10]. Among them, the literature review of Marques et al [7] surveys the various systems for high-cycle fatigue testing with uniaxial and multiaxial random loadings.…”

“…The paper by Marques et al [9] is, instead, focused on evaluating the sampling variability of the fatigue damage computed in one single nonstationary time history. Damage variability is tackled by means of confidence intervals, which are constructed from the damage values of disjoint segments and blocks into which the nonstationary time history is subdivided.…”

Development of a FEM procedure for evaluating the pressure profile in the industrial wheel and fatigue strength analyses

“…The goal of this article is the fatigue study of a wheel rim for earthmoving vehicles [1], [2]. In particular, we want to identify the distribution of loads acting on the fixed flange (Fig.…”