框架结构体系的可靠性分析

Reliability Analysis of Frame Structure System

在经典概率假设和二态假设基础上,提出了中介状态的观点,认为结构及结构体系均具有安全、中介、失效三种工作状态。可靠性分析的结果应是求出其安全概率PR、中介概率PM和失效概率PF,它们联合起来构成可靠性向量[PR,PM,PF]。采用随机事件的条件概率的运算法则,引入失效模式间的条件关联系数来反映结构之间的失效相关性。通过对大量地震震害调查,建立了同一工程项目的基本条件关联系数的近似处理方法。借用传统的一次二阶矩法求解框架结构体系遭受地震作用时的可靠指标和失效概率,与考虑中介状态和失效相关时的框架结构的可靠性向量相比较,各自求出的失效概率均可满足工程精度要求,但考虑中介状态和失效相关时的可靠性分析方法更为简单。

Based on Sutra probability hypothesis and two-condition hypothesis, the viewpoint of intermediate state is put forward, that is, any structure or structural system may be in the state of safety, failure or in between. By reliability analysis, such parameters as safety probability (PR), intermediacy probability (PM) and failure probability (PF) should be found out to be combined into a reliability vector [PR,PM, PF]. Adopting the algorithm of conditional probability of random events, the coefficient of conditional connection between failure models may be introduced to show the failure relevance between structures. By investigating into a large number of earthquake disasters, a method of approximately treating the relevant coefficients of essential conditions of the same project is established. Using the traditional method of reliability analysis, the reliability method of reliability analysis, the reliability index and failure probability of a frame structure system when suffering from seismic effects can be found out. Compared with the reliability vector of a frame structure when considering the relevance between intermediate state and failure, the failure probability worked out respectively can meet the requirement of engineering precision, but the method of reliability analysis considering the relevance between intermediate state and failure is simpler.