Fatigue Reliability Analysis of Steel Crane Girders Considering Influence of Low Stress Range

Abstract:

Fatigue reliability analysis method for steel crane girders is discussed in the paper. Firstly, fatigue failure limit state equations are developed in which two factors are considered such as the variable amplitude fatigue damage reduction caused by low stress range and the growth in number of fatigue cyclic loading. Next, the statistical properties of random variables in the limit state equation are investigated. Both the first order second moment method and Monte Carlo simulation technique are employed to calculate the fatigue reliability index. Then, a case study is carried out to investigate the effect of the above tow factors on fatigue reliability index. The current research results reveal that fatigue reliability index of steel crane girders increases significantly after considering fatigue damage reduction of low stress range，but it decreases as the growth rate in number of fatigue cyclic loading increases. Finally, a few of suggestions are given for fatigue design of steel structures.