雨流计数法又可称为“塔顶法”,是由英国的Matsuiski和Endo 两位工程师提出的, 距今已有50 多年。雨流计数法主要用于工程界, 特别在疲劳寿命计算中运用非常广泛。把应变-时间历程数据记录转过90°,时间坐标轴竖直向下, 数据记录犹如一系列屋面, 雨水顺着屋面往下流, 故称为雨流计数法。雨流计数法对载荷的时间历程进行计数的过程反映了材料的记忆特性，具有明确的力学概念，因此该方法得到了普遍的认可。(The rain stream counting method, also known as the tower top method, was proposed by two engineers in the UK, Matsuiski and Endo, for more than 50 years. The rain flow counting method is mainly used in the engineering field, especially in the calculation of fatigue life. Record the strain time history data by 90 degrees, and the time axis is vertical downward. The data record is like a series of roof. The rain water flows down the roof, so it is called the rain flow counting method. The counting process of the rain flow counting method reflects the memory characteristics of the material and has a definite mechanical concept. Therefore, this method has been widely accepted.)