摘要
非概率可靠性指标本质上是一个用于评估结构安全的“指数”,缺乏概率化的解释,当非概率可靠性指标小于1时难以判断结构的安全性。非概率集合可靠度其本质是在非概率可靠性指标小于1的情况下对结构可靠性的度量,强调支撑区域与失效区域重叠的情况,并隐含均匀分布假设,这显然与实际不符合。本文进一步研究了非概率可靠性模型,考虑了基本变量在不确定域内部的分布情况,并改进了非概率可靠度模型。基于改进的非概率可靠度模型推导了非概率可靠度与概率可靠度的关系,基于此建立了非概率可靠性指标与概率可靠性指标的数学转换关系。最后,建立了基于改进的非概率可靠度模型非概率可靠性指标与概率可靠性指标的数学关系的可靠性评估方法。该方法提供了非概率可靠性指标小于1时,非概率凸模型的非概率可靠性分析的概率化评估结果,避免了在基本变量的原始样本数据不足情况下进行可靠性评估结果的不准确和非概率可靠性评估结果偏于保守而造成的工程浪费。
The non-probability reliability index is essentially an"index"used to assess the safety of a structure,and lacks a probabilistic interpretation,and it is difficult to judge the safety of a structure when the non-probability reliability index is less than one.The non-probability aggregate reliability is essentially a measure of structural reliability when the non-probability reliability index is less than 1.It emphasizes the overlap between the support region and the failure region and implies the assumption of uniform distribution,which is obviously not consistent with the reality.In this paper,the non-probability reliability model is further investigated by considering the distribution of the fundamental variables inside the uncertainty domain,and the non-probability reliability model is improved.The relationship between non-probability reliability and probability reliability is derived based on the improved model of non-probability reliability,and the mathematical conversion relationship between non-probability reliability index and probability reliability index is established based on this.Finally,a reliability assessment method based on the mathematical conversion relationship between non-probability reliability index and probability reliability index is established.The method provides probabilistic assessment results of non-probability reliability analysis of non-probability convex model when the non-probability reliability index is less than 1.It avoids the inaccuracy of reliability assessment results when the original sample data of the basic variables are insufficient and the engineering waste caused by the conservative non-probability reliability assessment results.
作者
李书雅
LI Shu-ya(School of Civil Engineering and Architecture,Wuhan Engineering University,Wuhan 430074,China)
出处
《价值工程》
2023年第12期145-149,共5页
Value Engineering
关键词
可靠度
椭球凸模型
可靠性指标
reliability
ellipsoidal-convex-model
reliability index
