信息熵-层次分析法组合赋权的FMEA方法

FMEA Method with Combinatorial Empowerment of Information Entropy and Analytic Hierarchy Process

针对传统失效模式及影响分析(FMEA)方法有效性受到专家评估的主观性、不确定性,以及专家权重分配不合理等局限,将信息熵法与层次分析法结合使用,联合改善FMEA技术流程,形成一种信息熵—层次分析法组合赋权的FMEA方法。应用模糊集理论,引入三角模糊数,将定性的专家评估结果去模糊化。灵活运用趋于客观、定量的信息熵法和无需大量数据支撑的层次分析法,综合确定决策矩阵,合理分配专家权重。由风险的严重度(ESR)、发生度(OPR)、检测度(DDR)综合评定风险优先指数(RPN),得出各失效模式的风险排序。该方法可以以偏离度、置信度等指标作为指导,科学地分配权重,使得评估结果更合理、RPN值更准确、失效模式风险排序更客观。将改进的FMEA方法应用于某变距摇臂产品,残余应力下降13%,显著提高了产品质量。

In view of the limitations of the traditional failure mode and effect analysis(FMEA)method,such as subjectivity and uncertainty of expert evaluation and unreasonable distribution of expert weights,the information entropy method and analytic hierarchy process were combined to improve the FMEA technological process,thus forming an FMEA method with combinatorial empowerment of information entropy and analytic hierarchy process.By applying the fuzzy set theory and introducing triangular fuzzy number,the qualitative expert evaluation results were deblurred.Flexible use of information entropy method with objectivity and quantification and analytic hierarchy process with no need of a large amount of data support were carried out so as to comprehensive determine the decision matrix and rationally distribute the expert weight.The risk priority number(RPN)was comprehensively evaluated by the extent of severity of risk(ESR),occurrence probability of risk(OPR)and detection degree of risk(DDR),and the risk ranking of each failure mode was obtained.Such a method can be guided by indicators such as deviation and confidence to scientifically allocate the weights,which makes the evaluation results more reasonable,the RPN value more accurate and the failure mode risk ranking more objective.By applying the improved FMEA method into a variable-pitch rocker arm product,the residual stress decreases by 13%,which significantly improves the product quality.