关键词: 动态仿真, 疲劳剩余寿命, 应力谱, 雨流计数法

Abstract: It is necessary to obtain the stress spectrum of structural fatigue accounting point in order to estimate the fatigue residual life of metal structure of overhead travelling crane and ensure crane safety. The characteristic parameters of stress spectrum are lifting weight, lifting position, unloading position and whether through the midpoint of span. The probability distribution model of the characteristic parameters is built with the data by collected characteristic parameters on the spot and statistical tested. Random samples of the characteristic parameters are produced with the Latin hypercube sampling (LHS). Stress-time history of the fatigue accounting point is calculated by dynamic simulation model and double parameter stress spectrum is obtained by rain flow counting model. Fatigue residual life is estimated by Forman formula. Prototype simulated with the above method, the 10 levels stress spectrum is obtained in detection period, and the fatigue residual life is estimated as 32.8 years. The error of remaining fatigue life is 6.26% between in simulation stress spectrum and test stress spectrum. It is feasible that test stress spectrum were replaced by simulation stress spectrum for the remaining fatigue life assessment. The method has the merit of short cycle, low cost based on the combination strategy of “testing, statistics, sample and contrast” for load spectrum acquisition for overhead travelling crane and the remaining fatigue life assessment.

Key words: Dynamic simulation, Fatigue residual life, Rainflow counting, Stress spectrum