A method of failure analysis for failure modes and effects analysis based on stress environmental model

摘要

Computer aided analysis for Failure Modes and Effects Analysis (FMEA) is an important development direction. Failure analysis (failure mode and failure mechanism analysis) is the most critical and the most difficult step in implementation of FMEA. The procedure of failure analysis is lack of formal and standardized method, which hindering the computer integrated process. In face of complex products, the cost of time and manpower is very large and the analysis result is usually inconsistent, redundant and incomplete. Therefore, the accuracy of result cannot be guaranteed. To solve the above problems, this paper proposes a method of failure analysis for FMEA based on stress environmental model. The engine cylinder is used as an example to explain the method. Firstly, the source and classification of stresses are systematically studied and the corresponding stress identification rules is put forward according to operating conditions of product; secondly, stress environmental model of part or component is established based on the relations and constraints among stresses; finally, an analysis method with formal structure is established through analyzing the characteristics of failure mechanism and failure mode, and the results were summarized based on the analysis of engine cylinder. The model based analysis method presented in this paper can effectively ensure the accuracy of analysis result, and the analysis procedure with formal and standardized properties is also convenient for computer integration at the same time.