摘要
针对榫连接结构微动疲劳寿命不确定性计算问题,发展了改进蒙特卡洛抽样方法,其采用贝塔分布抽样和双峰正态分布抽样方法对变量进行抽样,然后基于重要抽样方法的思想推导得到对应变量分布特征的失效概率,并建立了相应的失效概率评估流程。结合非线性功能函数研究了分布参数、缩放参数和平移参数对改进蒙特卡洛抽样方法失效概率评估性能的影响。结果表明:贝塔分布抽样能有效平衡中心区域和边缘区域样本的分布,但缩放参数过小会导致样本只能落入部分失效区域,影响失效概率评估;平移参数过小会使双峰正态分布抽样趋于简单随机抽样,过大则会导致落在概率密度较大的失效区域的样本量减少,存在最优值。相同收敛准则下双峰正态分布抽样次数比简单随机抽样小一个数量级,且优于贝塔分布抽样。基于双峰正态分布抽样,对风扇叶片榫头微动疲劳寿命进行105次蒙特卡洛模拟仿真,计算得到其失效概率为0.0464%,全局灵敏度指标分析表明拉伸压强对榫连接结构微动疲劳寿命失效概率影响最为显著。
Considering the uncertainty analysis of fretting fatigue life of tenon structure,the modified Monte Carlo sampling method is proposed,which utilizes beta distribution sampling and bimodal normal distribution sampling methods to sample variables.Based on the theory of importance sampling,the failure probability of corresponding variable distribution characteristics is derived,and the corresponding failure probability evaluation processes are built.The effects of distribution,scaling,and translation parameters on the performance of failure probability estimation of the proposed method are investigated by using the nonlinear functional function.Results indicate that the distribution of samples in central and edge region are effectively balanced by beta distribution method.However,too small scaling parameter can only cover partial failure regions,affecting the evaluation of failure probability.There exists an optimal translational value for bimodal normal distribution sampling methods,since too small will make little change and too big leads to less distribution in failure zone with high probabilities.Compared with simple random sampling method under the same convergence criteria,one magnitude less sample size is achieved for bimodal normal distribution,and it also performs better than beta distribution sampling method.Based on this method,105 times of Monte Carlo simulation is conducted on the fan blade tenon,whose failure probability of fretting fatigue life is calculated to be 0.0464%.The global sensitivity index analysis shows that the tensile pressure has the most significant impact on the failure probability of fretting fatigue life of the tenon structure.
作者
陈实
张屹尚
张嘉诚
徐逸晗
孙凯
CHEN Shi;ZHANG Yishang;ZHANG Jiacheng;XU Yihan;SUN Kai(AECC Commercial Aircraft Engine Co.,Ltd.,Shanghai 200241,China;Shanghai Center of Research for Commercial Aircraft Engine Engineering Technologies,Shanghai 200241,China)
出处
《兵器装备工程学报》
CAS
CSCD
北大核心
2023年第9期195-202,共8页
Journal of Ordnance Equipment Engineering
基金
国家自然科学基金项目(52205224)
上海科技启明星计划项目(21QB1406300)
国家科技重大专项项目(J2019-IV-0012-0080)。
关键词
蒙特卡洛
贝塔分布
双峰正态分布
失效概率
榫连接结构
Monte Carlo
beta distribution
bimodal normal distribution
failure probability
tenon structure
