【摘要】 含缺陷压力容器的疲劳分析是石油化工行业的一个重要课题,通过分析影响裂纹扩展寿命的多个随机因素及使用疲劳寿命模型,讨论了裂纹尺寸的计算方法。考虑压力容器所承受载荷、材料断裂韧度及裂纹尺寸等参数,使用一次二阶矩法和Monte Carlo法,得出了在一定可靠度下的疲劳裂纹扩展寿命,计算了一定使用寿命时结构的失效概率,比较了不同初始裂纹尺寸对疲劳寿命的影响。算例表明,此方法可为含裂纹结构的概率损伤容限评估提供一定的理论依据。更多还原

【Abstract】 The fatigue analysis of the pressure vessels is an important task in the petroleum chemical engineering.By analyzing stochastic of effect on the fatigue crack propagation life,fatigue life model was used.The calculation methods for crack size are discussed.Considering the random characters of the loads,material fracture toughness,defect sizes and other parameters,the fatigue crack propagation life under a certain reliability and failure probability under a certain life are obtained by using the first order second moment method and Monte Carlo method.Fatigue life of different crack sizes was compared.An example was used to explain its application in reliability estimate of fatigue life and its engineering significance.It was suitable to the probabilistic damage tolerance evaluation of structures including all kinds of cracks.更多还原