The standardization of quality assessment of special metallurgical cranes based on design risk analysis

The article critically analyzes the standards for assessing the quality of the supporting structures of special bridge metallurgical cranes. At the present stage, more than 80% of such cranes are operated outside the warranty period. The standards are aimed either at a finite number of operating cycles, or at objects of low complexity, in particular FMEA. To estimate the resource, the characteristic number, a generalized indicator of the supporting structure, is used. Risk analysis is a promising and recommended one today. The structural risk analysis is considered as an integral indicator for assessing the quality of the actual technical condition of a special metallurgical crane. The article is a continuation of a series on the study of the use of structural risk analysis for assessing the quality of structures of a metallurgical enterprise. Models of quality are given according to the following risk criteria: normal, maximum permissible, critical (catastrophic). The largest catastrophic events of a metallurgical enterprise have been studied for 70 years. The statement of the problem is formulated as follows: it is necessary to critically assess the current state of the standards and find their joint optimal parameters or put forward new requirements to create a draft of a new standard for assessing the quality of special metallurgical cranes operating outside the warranty period. An algorithm is presented that includes and refines modern standards, including FMEA. Quality is calculated as a function that changes over time, inversely proportional to the risk, taking into account the damage. The calculated values of the quality are obtained, which make it possible to relate the number of worked cycles, the acting stresses and deformations.