摘要
为预防起重机主梁的疲劳破坏事故的发生,针对起重机金属结构既存在随机变量又存在区间变量的情况,提出基于概率-非概率混合模型的结构可靠性分析方法对起重机金属结构疲劳可靠性进行分析。根据断裂力学Paris公式建立疲劳裂纹扩展寿命估算的混合模型,首先根据结构疲劳失效准则建立一级功能方程,在其中的随机变量取其实现值的条件下,进行非概率可靠性分析;再根据“非概率可靠度指标大于1结构可靠”这一理论建立了二级功能方程,并进行随机可靠性分析。通过数值和工程实例验证,与传统的概率可靠性分析相比,这种分析方法更符合实际也更安全。
There are both random variables and interval variables for the crane metal structure,in order to prevent the fatigue damage accident of the main girder of the crane,the structural reliability analysis method based on the probability-non-probability hybrid model is proposed to evaluate the fatigue reliability of the crane metal structure in this paper.According to the paris formula of fracture mechanics,the hybrid model of fatigue crack growth life estimation is established.Firstly,the firstorder functional equation is established according to the structural fatigue failure criterion;under the condition that the random variable takes its realization value,the non-probabilistic reliability analysis is carried out.Then a two-level functional equation is established based on the theory of non-probabilistic reliability index is greater than 1 and the structure is reliable,and random reliability analysis is performed.Through the numerical and engineering examples,this analysis method is more realistic and safer than the traditional method of probabilistic reliability analysis.
作者
李建明
丁谦
LI Jian-ming;DING Qian(Shanxi Meiyuan Yongxing Coal Industry Co.,Ltd,Taiyuan Shanxi 030054,China;School of Machinery Engineering,Taiyuan University of Science and Technology,Taiyuan Shanxi 030024,China)
出处
《机械研究与应用》
2020年第5期48-51,55,共5页
Mechanical Research & Application
关键词
疲劳寿命
可靠性分析
混合可靠性模型
不确定性
断裂力学法
fatigue life
reliability analysis
probability-non-probabilistic reliability model
uncertainty
fracture mechanics
