基于样本集聚原理的疲劳可靠性评估方法及其在零部件上的应用

发布时间：2017-12-27 17:40

本文关键词：基于样本集聚原理的疲劳可靠性评估方法及其在零部件上的应用　出处：《机械工程学报》2016年06期 　论文类型：期刊论文

【摘要】：针对随机载荷下的疲劳可靠性,为能实现用小样本量的或大分散性的寿命数据获得较精确的寿命评估结果,基于样本集聚原理,改进应力-寿命关系曲线的获得方法,介绍逐渐缩小区间搜索方法和考虑材料分散性和随机载荷下的疲劳可靠性模型。逐渐缩小区间搜索方法的核心思想是区间逼近,每次搜索循环后均会缩减最优值的范围,至满足设定容差的结果停止搜索,并拟合应力-寿命关系曲线。基于此关系曲线,由确定应力到随机应力,再到服役工况种类的随机性,逐步建立疲劳可靠性模型。应用提出方法评估一服役后铝合金构件的疲劳寿命。结果表明,逐渐缩小区间搜索方法可在短时间内获得高精度的P-S-N曲线,提出的疲劳可靠性模型贴近工程,传统疲劳可靠性模型的结果偏于保守。
[Abstract]:According to the fatigue reliability under random load, to achieve a more precise result for life evaluation of small sample size or large dispersion of life data, sample clustering based on the principle of improved method should be obtained as a function of stress - life, the gradually narrowing the range of search methods and considering the material dispersion fatigue reliability model and random load under the. The core idea of narrowing the interval search method is interval approximation. After every search cycle, the range of the optimal value will be reduced, and the search result will be stopped to meet the set tolerance, and the stress life relation curve will be fitted. Based on this relationship curve, the fatigue reliability model is gradually established by determining the randomness of stress to random stress and then to the types of service conditions. The method is applied to evaluate the fatigue life of aluminum alloy components after service. The results show that the P-S-N curve with high accuracy can be obtained in a short time by narrowing the interval search method. The proposed fatigue reliability model is close to engineering and the result of traditional fatigue reliability model is conservative.
【作者单位】：东北大学现代设计与分析研究所;东北大学航空动力学装备振动及控制教育部重点实验室;
【基金】：国家自然科学基金(51335003) 辽宁重大装备制造协同创新中心资助项目
【分类号】：O346.2
【正文快照】： 0前言*疲劳是工程中常见的失效形式之一,指定存活率的应力-寿命曲线(P-S-N曲线)常被用来评估疲劳构件的可靠性[1-3]。而试验周期长、成本高等因素限制了P-S-N曲线的精度,进而影响了构件疲劳可靠性的准确性。再者,确定基层失效原因是可靠性分析的关键[2]。因此,利用小样本P-S-N

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