Comprehensive reliability allocation method for CNC lathes based on cubic transformed functions of failure mode and effects analysis

Abstract

Reliability allocation of computerized numerical controlled(CNC) lathes is very important in industry. Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components, which is not applicable in some conditions. Aiming at solving the problem of CNC lathes reliability allocating, a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis(FMEA) is presented. Firstly, conventional reliability allocation methods are introduced. Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated. Subsequently, a cubic transformed function is established in order to overcome these limitations. Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence. Designers can choose appropriate transform amplitudes according to their requirements. Finally, a CNC lathe and a spindle system are used as an example to verify the new allocation method. Seven criteria are considered to compare the results of the new method with traditional methods. The allocation results indicate that the new method is more flexible than traditional methods. By employing the new cubic transformed function, the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.

A reliability allocation method of mechanism considering system performance reliability

“…For example, the difference between severity level 1 and severity level 2 should differ from that of level 9 and level 10. Therefore, some researchers have proposed a method to calculate the allocation weight by transforming the ranking . The severity transforming formula is as follows: where α is an undetermined coefficient.…”

“…The maximum severity of all the failure modes of a subsystem and an improvement effort scale based on failure rate was introduced in the method. Based on a cubic transformation functions of FMEA, Yang et al presented a reliability allocation considering failure severity. Rajeevan established a failure rate allocation method based on Markov model from the perspective of availability (comprehensive consideration of reliability and maintainability).…”

Low Carbon-Oriented Optimal Reliability Design with Interval Product Failure Analysis and Grey Correlation Analysis

“…In particular, precise and advanced CNC machines account for 65% of the whole equipment investment. Hence, the investigation of CNC lathes for the optimal reliability design is very important [19,20,45]. The target reliability for the vertical CNC lathe is required to be 0.875.…”

“…Hence, product failure is an inevitable aspect of optimization design based on reliability. Usually, the effect of product failure is measured by the failure frequency and failure severity [17,18], and some scholars recently [19][20][21][22][23] handled the failure effect in product reliability optimal design with risk priority number (RPN) information produced by the qualitative analysis and quantitative calculation of failure mode effects analysis (FMEA). FMEA is defined as an analysis model to recognize various failure modes occurring in a system and the corresponding impacts on the whole product function.…”

Reliability Modeling of Electromechanical System with Meta-Action Chain Methodology

“…In the previous research, the failure modes and effects analysis (FMEA) has been often used to determine the criticality and frequency of failure. Yang et al [8] presented cubic transformed functions of FMEA. Kim et al [9] summarized the limitations of the FMEA methods.…”