Description:
<jats:title>Abstract</jats:title><jats:p>A new criterion of selecting the small load truncation level for simplification of fatigue test spectrum was developed, which is based on the principle that the truncated spectrum has the same fatigue life distribution as the original spectrum. Considering the influence of uncertainties of material fatigue performance and load spectrum on the fatigue life distribution, the relation between the distribution difference and the small load truncation level was established. According to the designed tolerance value of distribution difference, the appropriate small load truncation level could be determined accordingly. The selection criterion was verified by the fatigue tests of LC4CS aluminum alloy smooth sheet specimens. The results show that good simplification effect of spectrum can be achieved based on the criterion.</jats:p>