Prediction and evaluation of fatigue life under random load based on low load strengthening characteristic

To improve the shortcomings of peak over threshold (POT) extrapolation method and reflect the diversity and dynamics of road conditions, an improved POT extrapolation method to reconstruct the load sequence in the middle of threshold is proposed. Based on the improved extrapolated load, the distribu...
Ausführliche Beschreibung

To improve the shortcomings of peak over threshold (POT) extrapolation method and reflect the diversity and dynamics of road conditions, an improved POT extrapolation method to reconstruct the load sequence in the middle of threshold is proposed. Based on the improved extrapolated load, the distribution characteristics of mean and amplitude are analyzed and the two-dimensional joint probability distribution is established. To discuss the influence of low load strengthening characteristics on fatigue life under random load, based on the two-dimensional joint probability distribution, the theory of low load strengthening is introduced in compiling load spectrum. The fatigue life predicted by 8-level load spectrum and 10-level strengthened load spectrum are compared with the test results, respectively. Which verifies the effectiveness and accuracy of life prediction based on improved POT extrapolation and low load strengthening under random load. Ausführliche Beschreibung