极值风速风向的联合概率密度函数

摘要

基于最大熵原理,构建极值风速风向的联合概率密度函数,并与Copula函数建立相互关联.以我国某地的极值风数据为例,建立极值风速的Gumbel分布模型以及对应风向的二阶混合von Mises分布模型;使用非线性参数优化算法确定极值风速风向的联合分布模型.采用该模型计算各风向角下不同重现期的基本风速值,并与建筑结构荷载规范值(GB 50009-2012)进行对比.结果表明,联合分布模型能够有效表征实际风速风向的概率分布特征.分别采用Spearman秩相关系数和线性-角度变量相关系数对模型的相关性予以验证,探究模型的有效性.%A joint probability density function for representing both extreme wind direction and speed was constructed based on the maximum entropy principle and established relationship with Copula function.Taking the extreme wind records of somewhere in China as an example, the Gumbel distribution model for extreme wind speed and the second order mixture von Mises distribution model for corresponding wind direction were established respectively;then the joint probabilistic distribution model was determined using nonlinear optimization algorithm.Reference wind speeds of different recurrence intervals in all directions were calculated by applying the model, which were compared to the code values of building structure load (GB 50009-2012).Results show that the proposed joint probabilistic model describes the characteristics of the distribution of actual extreme wind speed and direction effectively.The correlation of joint probabilistic model was verified by checking the Spearman rank and the linear-angular correlation coefficient respectively, which proves its validity.