Reliability Assessment of Machine Tools Considering Multi-effects of Working Conditions

Abstract

Undertaking varying working conditions is common for a machine tool. One single reliability model for determining a single effect is not suitable for the reliability evaluation of machine tools due to the multi-effect of working conditions on the reliability of machine tools. This paper proposes a generalized model using hazard functions and Weibull distribution to assess the reliability of machine tools under different effects of working conditions. This model considers three effects, including the proportional hazard, time, and additive hazard effects. The distribution of time effect is discussed. Furthermore, a secure parameter estimation method is presented to calculate the proposed reliability model. A case study based on field data is presented. The proposed model is compared with classical reliability models. The result shows that the proposed model has better goodness of fit for the realistic cumulative distribution of machine tools.