Optimal Design of Constant-Stress Accelerated Degradation Test for Motorized Spindles

Motorized spindle is a key functional unit of CNC machine tools, the reliability of which has a great impact on the reliability of machine tools. Optimal design can effectively shorten the accelerated degradation test period of motorized spindle and improve the accuracy of its reliability evaluation. Aimed at the occasion that optimization results would be inaccuracy when the alternative set is chosen improperly through the existing methods, a new optimization method of constant-stress accelerated degradation test with multiple kinds of stresses is proposed. Particle swarm optimization is used to establish an alternative set, and then the simulation data is generated by Monte Carlo simulation. In the entire process of optimization design, two kinds of optimization criteria are adopted to guarantee the comprehensiveness of results. Finally, the optimum accelerated degradation test plan is obtained through the statistical analysis method. At the end of paper, the proposed method is applied to a numerical example to verify its effectiveness.