Load Spectrum Calculation and Probabilistic Fatigue Life Analysis of Escalator Truss Structure

Escalators are a widely used means of transportation. The escalator truss structure is subjected to random loads during working operation, and fatigue failure of escalator truss structure occurs from time to time. In this study, the pedestrian load time history of escalator in a subway station was counted by means of real measurements. The stability of the collected data was verified by the round-trip test method. By using rain-flow counting method to process the load time history, the random load spectrum of escalator structure was obtained. And the eight-level fatigue load spectrum of escalator truss was simplified. To study the probabilistic characteristics of the truss material, the P-S-N curve of the truss material was obtained based on the subsample method and modified to obtain the P-S-N curve of the truss structure. Finally, the fatigue life of the dangerous part of the escalator truss structure was predicted by using Miner liner fatigue accumulation damage theory. The probabilistic life of the truss structure was obtained. Based on the finite element simulation analysis, the fatigue life of the truss structure is verified, and the results show that the simulation results are basically consistent with the calculation results, which proves the effectiveness of the method of this paper.