Application Research On Failure Modes And Effects Analysis Of Metallurgical Bridge Crane

Metallurgical cranes be used in metallurgical workshop primarily for steelmaking, forging, heating and other metallurgical processes such as lifting materials, which has high utilization, agencies running and frequently braking and lifting loads near or equal to the rated load. Meanwhile, the working conditions of metallurgical workshop’s environment is high temperatures, dust and poor. Because of the character of can is various loading, face greater risk, risk factors, work environment more complex, the number of accidents is high. According to incomplete statistics, during the years of 2006 ~2011 in crane accidents occurred is 370, metallurgy crane accidents is 128, which is 37.54% of the total number of accidents, it ranks first in all types of crane accidents. Therefore, failure mode and effects analysis for the metallurgical cranes is necessary. Not only can effectively reduce the incidence of metallurgy crane faults and improve system reliability, but reducing or eliminating the number of accidents, reducing transport and maintenance costs, improving the economic efficiency of enterprises. Application of FMEA in metallurgical cranes, this paper as follows:(1) Through statistics of accident cases in recent years, determined that percent of bridge crane accident, easy part of accident, easy to failure part of equipment and structure. According to accident cases, sums up key parts of metallurgical cranes and metal structural failure modes, and each failure mode and mechanism.(2)The 450 t metallurgical cranes as the object of study, analyze it by traditional forms of FMEA analysis completely. Based on fuzzy confidence algorithm and grey incidence decision, improved calculation of failure risk assessment with 450 t metallurgy crane’s main hoist mechanism. In traditional FMEA the risk priority rating, there are many subjective factors in the rate of occurrence, detection and evaluation on simple. By fuzzy confidence Algorithm, the form of confidence, and fuzzy rating to evaluate the three risk factors. When levels of the failure mode risk factor cannot be determined, using confidence interval evaluation of structures or incomplete evaluation, which can avoid arbitrary under the condition of incomplete information and improve the accuracy and applicability of FMEA risk evaluation.(3)Based on FMEA and condition monitoring of metallurgical cranes, developed metallurgy crane visualization system of health monitoring and forecasting. Then monitoring vulnerable areas for 450 t metallurgy crane structural stress, real-time monitoring data available for equipment managers understand the stress state of key parts of crane metal structure. As the fatigue life of the structure is estimated with the stress time curve extrcacted by facility managers, the fatigue state of structure is determined. And then, processing potential failures of structure in advance,eliminate the failure in latency period.