考虑Kriging模型的击针疲劳强度可靠性分析

击针是枪械的重要部分,随着射击次数的增加,击针可能产生断裂,影响正常使用。疲劳断裂是击针失效的主要因素,而采用随机有限元模型的击针疲劳可靠性分析计算量大,为此提出了一种考虑疲劳损伤退化过程的Kriging模型分析方法。首先利用有限元对部件进行应力应变分析,产生了计算疲劳损伤所需的数据,再由Kriging模型模拟结构应力函数,利用Neuber局部应力应变分析法求出击针的疲劳损伤,最后由Kriging模型结合蒙特卡洛方法模拟抽样随机因素下的单发射击时的损伤大小,拟合了击针疲劳损伤退化量的分布函数,并由此退化数据分析评估了击针的可靠性。结果表明:该方法较为准确且计算量小,更适用于疲劳可靠性问题的快速评估。

Reliability Analysis of Fatigue Strength of Firing Pin Considering Kriging Model

Firing pinis an important part of firearms,with the increase in the number of firing,it may be broken,affecting the normal use. Fatigue fracture is the main factor in the failure of the pin,and it is computationally large for fatigue reliability analysis of pin to use stochastic finite element model,thus a Kriging model analysis method considering the fatigue damage degradation process is proposed.First,finite element method is used to analyse the stress-strain of the pin,getting the necessary data for fatigue damage,thenKriging model is used to simulate stress function of the pin,fatigue damage of the pin is obtained by using the Neuber local stress and strain analysis method. Finally,the Kriging model is combined with the Monte Carlo method to simulate the damageof single shot under random sampling,and the distribution function of the sample histogram is obtained by fitting fatigue damage of the pin. The reliability of the pin is evaluated by the degradation data analysis.The result shows that the method is more accurate and computationally small,and more suitable for rapid assessment of fatigue reliability problems.