FMECA-模糊综合分析法在自旋滑车桥轴风险评价中的应用

FMECA法是一种定性的分析方法,它通过对目标系统下各单元的功能、潜在故障模式、故障原因、故障率及严重性进行分析,找出危险性较高的故障模式和设计中的薄弱环节。模糊综合分析法可以将定性的评价结果以定量的形式表达,但其评价结果具有模糊性。提出了一种将FMECA法与模糊综合分析法相结合的评价方法,既可以减少模糊综合分析评价结果的模糊性,又可以将FMECA法的定性描述以定量的形式表达,使评价结果更加客观、合理。并以大型游乐设施中自旋滑车的桥轴为例,运用FMECA-模糊综合分析法对其进行风险评价,计算结果表明其风险等级较低,与实际检验结果相符。

Application of the FMECA-fuzzy comprehensive method to the risk assessment of the self-revolving pulley axle

This paper is inclined to introduce its work on the risk assessment of the axle of self-revolving pulley by using FMECA and fuzzy comprehensive analysis method,which serves as a highly significant part for guaranteeing the quality of such pulleys,for it has a direct effect on the successful operation of the entire system.It is just starting from the above need that we have chosen the FMECA (Failure Mode,Effects and Criticality Analysis) method to do the following qualitative analysis of such items of the system,as the function of the system,its failure modes,the failure causes,the failure rates and the deformation severity of the axle.As is well known,the commonest forms of the normal surface wear of the axle can be divided into four forms,that is,the adhesive wear,the abrasive wear,the surface fatigue wear and the corrosive wear.It is supposed that the fatigue fracture,the brittle rupture and the ductile fracture should be regarded as the three common failure forms of fracture of the axle and there exist two kinds of causes that should account for the excessive deformation of the axle,that is,the excessive elastic deformation and the excessive plastic deformation.It is the duty of the experts that can classify and categorize all the aforementioned failure modes and severities.And they are to be responsible for scoring all the failure rates and severities of the failure mode and calculating the RPN.AHP so as to work out the weights of each evaluation factor.Though the fuzzy comprehensive analysis method can evaluate the risk of each subsystem and finally work out the risk value of the target,it remains very hard to get the objective results of the risk assessment of the axle for it is inevitable for the fuzziness and uncertainty of the fuzzy comprehensive evaluation methods to get rid of such consequences.Therefore,we propose to combine the FMECA and fuzzy comprehensive analysis method by integrating the both into one so as to reduce the fuzziness in the evaluation results and produce somewhat joint evaluation results quantitatively and qualitatively in a comprehensive manner.The results of our simulated application in the above mentioned joint way show that the axle has a lower level of risk and the results prove to be well in accord with the actual tests.