Reliability modeling and analysis of heavy-duty CNC machine tool spindle under hybrid uncertainty

Abstract

Heavy-duty CNC machine tools have been used to process and manufacture the products and the key components with concerns the national economy and defense security, and the quantity of heavy-duty CNC machine tools measures the industrialization level and the comprehensive strength of a country. Compared with the general machine tools, heavy-duty CNC machine tools have a more complex system structure, smaller size sample, less experimental data, incomplete information, more complex failure mechanism and other characteristics. The heavy-duty CNC machine tools as well as its sub-systems are often influenced by hybrid uncertainty and the correlated failures of different components. Therefore, the existing reliability technologies cannot be applied directly, thus new reliability technologies for specific to heavy-duty CNC machine tools are needed. Aiming at the problems analyzed above, this paper focus on the reliability modeling and analysis of heavy-duty CNC machine tool spindle under hybrid uncertainty. Firstly, this paper analyzed various uncertainty factors influencing the reliability of the heavy-duty CNC machine tool spindle and the limitations of the existing uncertainty quantification methods, constructed a unified framework for hybrid uncertainty quantification based on the imprecise probability theory. Secondly, based on the uncertainty quantification framework and stress-strength interference theory, this paper proposed an imprecise structural reliability analysis and modeling method for mechanical components. Finally, the models proposed in this paper were verified through the imprecise structural reliability analysis of a certain type of milling spindle, the imprecise structural reliability models under different failure modes are proposed. And the results are compared with the results calculated by Monte Carlo method. It has shown that the proposed method has a higher computational efficiency.