The importance of the enhanced FMECA in PHM design is described, and the shortcomings of the existing enhanced FMECA methods are given. Based on the existing enhanced FMECA methods, the meaning of the enhanced FMECA is modified, and the relation between the enhanced FMECA and the classical FMECA is analyzed. The new contents including the failure evolution characteristic analysis, the failure precursor analysis,the quantitative evaluations of failure diagnosis and prognostics are added. The complement information aboutthe existing contents including the failure symptom analysis, the layout of sensors and test points, and the failure diagnosis and prognostics method analysis is also given. The new table of the enhanced FMECA is created,and the flow of the enhanced FMECA is given. A brake control system for airplane wheels is selected to apply the enhanced FMECA method. The result of the case application shows the feasibility and validity of the enhanced FMECA method.%阐述了扩展FMECA在PHM设计中的重要性,以及现有扩展FMECA方法存在的不足.在现有扩展FMECA方法的基础上,对扩展FMECA的内涵进行了修正,分析了扩展FMECA与传统FMECA之间的关系.新增了故障演变特性分析、故障先兆分析、故障诊断与预测的定量评价等分析内容,并对现有的故障症状、传感器和测试点布局、故障诊断与预测方法等分析内容进行了补充.建立了新的扩展FMECA分析表格,并给出了扩展FMECA的实施流程.以某机轮刹车控制系统为案例,应用了扩展FMECA方法.案例应用结果验证了扩展FMECA方法的可行性和效果.
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