B级车轮铸钢疲劳可靠性S-N曲线重构方法

为实现任意可靠性水平疲劳强度设计、寿命预测和可靠性评定,提出了B级车轮铸钢疲劳可靠性S-N曲线的重构方法,应用Monte-Carlo模拟技术在可接受误差范围内重构了B级铸钢的疲劳极限和成组法S-N数据,依照常规法测定了B级铸钢中、短寿命范围的可靠性S-N曲线,应用概率疲劳极限外推法获得了包含中、短和长寿命范围的可靠性曲线。在此基础上,考虑工程应用实际情况,推导出了任意概率水平下的里程可靠性曲线。重构获得的疲劳极限及S-N数据最大模拟误差分别只有0.15%和0.07%,较好再现了原始数据,对曲线的外推使其合理性达到生产需要的104km以上,说明曲线重构方法可获得所需疲劳可靠性S-N曲线。

Reconstruction method of fatigue reliability S-N curves for railway wheel cast steel of grade B

In order to realize the reliability strength design, fatigue life prediction and reliability assessment at an arbitrary probabilistic level for railway wheel cast steel of grade B, a reconstruction method of fatigue reliability S-N curves was proposed, the fatigue limits and the S-N data were reconstructed by a technique of Monte-Carlo simulation with acceptable error range, the basic reliability curves in the middle and short life ranges were estimated by conventional method, the reliability S-N curves in the middle, short and long life ranges were established by probabilistic fatigue limit extrapolating method. Taking the practical situation of engineering application into account, the mileage reliability curves at arbitrary probabilistic level were deduced. The maximum simulation errors for the reconstructed data of fatigue limits and the S-N data are only 0.15% and 0.07% respectively, the extrapolated curves can cover the range of more than 104 km, it meets production demand, which shows that the reconstructed method is feasible. 7 tabs, 3 figs, 12 refs.