结构动力可靠度分析的矩方法

Structural dynamic reliability analysis based on moments approach

为了研究地震动作用下的随机结构响应,提出了一种结构动力可靠度的简化分析方法。首先,在首次超越破坏准则的基础上,采用极值分布描述建立了结构动力可靠度的等价功能函数表达,并定义了结构动力响应的安全裕量;然后,应用点估计法计算了等价功能函数响应值,进而计算出了前四阶中心矩,并引入了简化四阶矩方法求解结构动力可靠度指标及相应失效概率;最后,以受到随机地震动作用并具有随机结构参数的一榀框架的动力可靠度问题为例,与随机模拟方法计算结果对比,验证了建议方法的计算精度和计算效率。

A simplified method for structural dynamic reliability analysis of stochastic structures subjected to ground motion was proposed.On the basis of exceeding the failure criterion for the first time,the equivalent functional function of structural dynamic reliability was established and the safety margin of structural dynamic response was defined by the description of extreme value distribution.Then,the point estimation method was used to calculate the response values of the equivalent functional functions,and then the first four order center distances were calculated.A simplified fourth-moment method was used to solve the structural dynamic reliability index and the corresponding failure probability.Finally,the dynamic reliability of a frame subject to random vibration and with random structural parameters was taken as an example,and the calculation accuracy and efficiency of the proposed method were verified by comparing with the calculation results of the stochastic simulation method.