结构延性系数的确定,目前无统一方法,致使采用不同方法求得的μ值相差甚大。对于屈服点不明显的P～⊿曲线,其关键是如何准确地确定⊿(?)(屈服位移)。本文针对国内外常用几种方法的缺点,提出双直线法。本法选用双直线模型来逼近实际曲线,并要求双直线满足下述条件:(见图1) There is no uniform method to determine the structural ductility coefficient, which results in a great difference in μ values ​​obtained by different methods. The key to the P~⊿ curve, where the yield point is not significant, is how accurately the ⊿(?) (yield displacement) is determined. This paper proposes a double-straight line method for the shortcomings of several commonly used methods at home and abroad. This method uses a double-line model to approximate the actual curve, and requires the double line to meet the following conditions: (see Figure 1)