A Framework for Health State Evaluation of the Complex Mechanical System With its Occurrence Probability of Failure Mode

Abstract

Safety and overall productivity of the complex mechanical system (CMS) are affected by their health state directly. In order to achieving accurate and effective health state evaluation (HSE) of the CMS, dependency and correlation among system, subsystem, component, failure mode and characteristic variable are revealed. Based on their dependency and correlation between failure mode and characteristic variable, two novel concepts, including occurrence probability of failure mode (OPFM) and degradation probability of characteristic quantity (DPCQ), are defined and their calculation function relation is established for the HSE of the CMS. A framework for HSE of the CMS based on the OPEM is proposed. This HSE method can deal with the CMS with characteristics such as the small number of characteristic quantity corresponding to a single failure mode, health state, the correlation between failure mode and characteristic quantity and so on. For quantitative HSE of the CMS,“failure mode-component-subsystem-system” can be realized by step-by-layer solution. Finally, this method has been verified by a case study, which can effectively avoid problems of redundancy of characteristic quantity, wrong selection of characteristic quantity, complex calculation relation and large amount of calculation data in the HSE of the CMS.

Keywords

• Asset integrity management
• complex mechanical system
• health state evaluation
• occurrence probability of failure mode
• prognostic and health management