摘要
结构体系可靠度是一个40年来尚没有得到很好解决的问题,即使对于理想弹塑性体系,经典的结构体系可靠度分析也往往会遭遇两个难以克服的困难:相关失效与组合爆炸。近年来,基于概率守恒原理的随机事件描述,提出了广义密度演化方程,从而将确定性系统和随机系统分析纳入到统一的理论框架之中。基于这一进展,结合结构非线性全过程分析的位移控制算法,本文推导了结构静力非线性发展过程的概率密度演化方程。采用纤维梁柱单元进行结构非线性分析,研究钢筋混凝土框架结构的体系可靠度,并与Monte Carlo法进行对比分析。研究结果证明了概率密度演化理论对结构体系可靠度分析的适用性。
In spite of nearly four decades of investigations, structural system reliability is still an unresolved issue. In classical system reliability theory encountered are the two obstacles, the correlation of failure modes, and the combinatorial explosion problems. Recently, based on the random event description of the principle of preservation of probability, a generalized density evolution equation has been established, and a family of original and effective approaches capable of capturing the instantaneous probability density functions of the responses of multi-degree- of-freedom linear and nonlinear systems developed. In the present paper, based on the above theory, namely the probability density evolution method （PDEM）, a generalized density evolution equation of the nonlinear evolution process of frames with loading parameter as the ＂time parameter＂ is derived, from which the probability density function of the ultimate capacity can be obtained. Combining such approach with structural nonlinear analysis based on the fiber beam-column elements, the system reliability of RC frames subjected to static loads is evaluated. The reliability of a 2-story 2-bay RC frame with random parameters is numerically investigated. Comparing with the Monte Carlo simulation, the proposed method is accurate and more efficient for the reliability analysis of RC frames.
出处
《土木工程学报》
EI
CSCD
北大核心
2008年第11期7-12,共6页
China Civil Engineering Journal
基金
国家自然科学基金委创新研究群体资助项目(50621062)
关键词
体系可靠度
概率密度演化理论
纤维梁柱单元
system reliability
probability density evolution method
fiber beam-column element
