水工钢闸门主梁模糊失效概率计算方法研究

为合理计算水工钢闸门主梁模糊失效概率，分别将主梁相对变形当作一个随机变量及三个变量的组合，采用积分法、当量随机化方法及蒙特卡罗法进行了计算。当相对变形为一个随机量时，采用积分法及当量随机化方法计算，两者的差别在于积分法用隶属函数描述模糊限值，当量随机化方法是将模糊限值当量作为一个随机量。当相对变形看作三个变量的组合时采用蒙特卡罗法进行计算，该方法考虑了三个变量的分布特性，更符合实际情况，模糊限值也用随机量表示。计算表明，积分法与当量随机化方法结果相近，验证了当量随机化方法的精度;蒙特卡罗法结果与相对变形服从正态分布时、用当量随机化方法计算的结果接近，故主梁相对变形服从正态分布更为合理。三种计算方法中，当量随机化方法计算失效概率相较于其它方法有计算过程简便，效率高的优点。

Study on fuzzy failure probability calculation method of hydraulic steel gate girder

This paper aims to reasonably calculate the fuzzy failure probability of the main girder of the hydraulic steel gate by taking the relative deformation of the main girder as a random variable and the combination of three variables in three different ways: the integration method，the equivalent randomization method and Monte Carlo method． When the relative deformation is taken as a random variable，the difference between the integration method and the equivalent randomization method lies in that the former method will use membership function to describe the fuzzy limit value which is taken as a random variable by the latter one． When the relative deformation is taken as a combination of the three variables，the distribution function of these variables is considered by Monte Carlo method which is more in accordance with the actual situation and the fuzzy limit value is also expressed with random variable． The results of these calculation show similarities between the integration method and the equivalent randomization method，and prove the accuracy of the equivalent randomization method． The result of Monte Carlo method is close to that of the equivalent randomization method which is used when the relative deformation follows a normal distribution． Consequently，it's more reasonable that the relative deformation of the main girder follows a normal distribution． Among these three methods，the equivalent randomization method has such advantages as simple calculation process and high efficiency in calculating the failure probability．