结构可靠度分析中作用的随机过程组合方法

结构可靠度分析应以直接描述作用随机变化的概率模型和随机过程组合方法为基础，但在目前的作用概率组合中，对由频遇值、准永久值参与组合的可变作用实际采用的是以最大值表达的随机变量组合方法，这将导致不合理的分析结果。依据可变作用的等时段平稳二项矩形波过程概率模型，确定与频遇值、准永久值超越比率对应的时段样本，提出可变作用频遇序位值和准永久序位值的概念，据此建立以作用序位值表达的随机过程组合方法和可靠度分析模型。该方法以随机过程理论为基础，具有明确、合理的工程概念，可准确反映作用组合的基本思想，得到合理的可靠度分析结果，从根本上克服了目前随机变量组合方法的缺陷。

Method for combination of actions based on stochastic processes in analysis of structural reliability

The analysis of structural reliability should be based on the probabilistic models describing directly the variety of actions and the method for combination of actions based on stochastic processes. However, the current method for combination of variable actions appearing with their frequent values or quasi-permanent values is actually the one based on random variables by maximum values expression, thus will lead to unreasonable results. According to stochastic model for variable action of equal time interval stationary binomial rectangular wave process, the interval samples corresponding to exceeded rates of frequent value and quasi-permanent value were determined, and the new concepts of frequent sequence values and quasi-permanent sequence values of variable actions were proposed. Consequently, the method for combination of actions based on stochastic process by sequence values expressions and models for reliability analysis were established. The proposed method is based on the theory of stochastic process, with clear and reasonable engineering concepts, thus can reflect accurately the ideas of actions combination, and derive reasonable results of reliability analysis, overcoming essentially the disadvantages of current method for combination of actions based on random variables.