【摘要】 给出了以特征应力为参量表示的结构细节的ａ－ｓ－Ｎ曲线。利用此曲线、等寿命曲线和线性累积损伤理论将恒幅载荷下的（ａＫ，ＮＫ）数据转换为谱载下的（ａＫ，ｔＫ）数据，再由（ａＫ，ｔＫ）数据确定当量初始缺陷（ＥＩＦＳ）分布。进而分析裂纹超越数概率和结构损伤度，完成结构耐久性分析更多还原

【Abstract】 The a-s-N curve expressed by characteristic stress of structural details is presented. Then the ( a K ,N K ) data under constant loading are transformed into the ( a K ,t K ) data under spectrum loading by using Goodman diagram and Miner’s rule,and equivalent initial flaw size (EIFS) distribution parameters are obtained by the ( a K ,t K ) data.Finally,the probability of crack exceedance and structural damage degree are calculated and the durability analysis is completed.更多还原