C级铸钢重构S-N曲线模型的研究

给定若干概率水平的常规疲劳可靠性S-N曲线只能做相应概率水平的疲劳设计与寿命预测,要实现任意可靠性水平的疲劳设计、寿命预测和失效率分布规律估计,需要重构广义概率疲劳可靠性S-N曲线.首先应用Monte Carlo模拟技术在可接受的误差范围重构C级铸钢的疲劳极限和成组法S-N数据,然后应用广义极大似然法测定其中短寿命范围的可靠性S-N曲线,最后应用概率疲劳极限外推法获得该材料长寿命范围的合理疲劳概率S-N曲线.

Research of reconstructed S-N curves model of the cast steel of grade C

The commonly fatigue reliability curves can do only reliability design and life prediction with the given reliability levels. For the realization of reliability design, fatigue life prediction and distributed failure rates at arbitrary reliability level, reconstruction of the fatigue reliability S-N curves is essential on an entire probability sense. The fatigue limits and the S-N data of railway grade C cast steel are first re-constructed by a Monte Carlo simulation with an acceptable error range. The basic reliability curves in the mid-and-short life regime are then estimated by the general maximum likelihood method. The reliability curves covering the long fatigue life regime are then established by a so-called probabilistic fatigue limit extrapolating method on an entire probabilistic sense