中文摘要：

针对老龄平台结构存在的多种退化失效因素，综合考虑疲劳失效、腐蚀失效和静强度失效这3种失效模式，建立每种失效模式的可靠度模型，并相应给出可靠度计算方法。通过相关系数研究任意两种失效模式之间的相互影响，进而提出两种计算3种退化失效模式全耦合作用下可靠度的方法：一是根据O．Detlevsen窄界限理论计算可靠度指标上、下限，二是通过将疲劳裂纹扩展和腐蚀退化引起的总抗力衰减引入静强度退化失效模型中，得到3种失效模式的耦合失效概率。实际算例结果表明：在不同服役阶段构件具有不同的主导失效模式；任意两种失效模式的耦合可靠度均低于单一失效模式的可靠度，3种失效模式耦合可靠度最低。

英文摘要：

Considering possible deterioration failure modes of aging platform members, including fatigue failure, corrosion failure and static strength failure, each reliability model was established and the corresponding computing approach was presented. The interaction between any two failure modes was analyzed through correlation coefficient. Then, two different methods were proposed to calculate the reliability of the component under three-failure-mode-coupling. One is the O. Detlevsen＇s narrow bounds theory, and the other is introducing the overall resistance deterioration including fatigue crack and corrosion to static strength failure model. The numerical results show that the platform member has different dominant failure modes at different service periods. The reliability index for any two-failure-mode-coupling is lower than that of any single failure mode, and the three-failure-mode-coupling is the lowest.