（内蒙古电力勘测设计院  呼和浩特 010020）
【提要】  从钢筋混凝土正截面承载力计算时的基本假定出发，建立了环形截面上各种应力图形的函数表达式，利用曲线积分的数学方法，推导出计算钢筋混凝土环形截面构件截面延性系数的数学公式。
【关键词】  钢筋混凝土  环形截面  延性系数  屈服  极限
Calculation for Crosssection Ductile Coefficient of Reinforced Concrete Ring Section Member/Sun Kejian（Inner Mongolia Power Exploration & Design Institute，Huhehaote 010020，China）
Abstract:Starting with the basic assumption while calculating the bearing capacity of the reinforced concrete normal section，the function expression is set up for different stress graphs on the ring section.By using the mathematical method of curve integrals，it derives the mathematical formula to calculate the crosssection ductile coefficient of RC ring section member.
Keywords:reinforced concrete；ring section；ductile coefficient；yield；limit