Optimization Design of Step Stress Accelerated Degradation Test for Motorized Spindle Based on <i>D_s</i>-Optimality

• Main Authors: Hongxun Zhao, Zhaojun Yang, Chuanhai Chen, Hailong Tian, Xiaoxu Li, Shizheng Li
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Applied Sciences
• Subjects: motorized spindle; step stress accelerated degradation test; test analysis; <i>D_s</i>-optimality; optimization design
• Online Access: https://www.mdpi.com/2076-3417/11/9/3832

In the accelerated degradation test (ADT) of motorized spindles, it is necessary to apply a variety of stresses to simulate real working conditions. However, the traditional accelerated test scheme optimization method does not consider the weight of various stresses in the test, resulting in the evaluation accuracy of important stress parameters in the model being too low. In order to solve this problem, an optimal design method of the step stress accelerated degradation test (SSADT) scheme for motorized spindles is proposed based on <em>D_s</em>-optimality. Firstly, the fault tree analysis (FTA) method is used to analyze the collected fault data of motorized spindles and screen the main stress. Then, the accelerated degradation model is established by using drift Brownian motion. Based on the <em>D_s</em>-optimality, the optimization variables and constraints in the test are determined, and the optimization model is established with the objective of minimizing the estimated variance of the main stress parameters in the acceleration model; additionally, the optimization steps are given. Finally, an example is given to verify the effectiveness of the method. Sensitivity analysis of the optimization results shows that the method has good robustness.