Two-stage accelerated life test model based on Weibull distribution

Aerospace products will go through multiple task stages in their life cycle. The existing accelerated life test (ALT) models are mainly aimed at a single task stage, so it is difficult to establish a relationship between the failure distribution of products under different stages. In this paper, two-stage ALT model with Weibull distribution is proposed. Assuming that the product life follows the Weibull distribution with different shape parameters and scale parameters in the two stages of ALT. On the basis of the tamper failure rate model, a flexible failure rate idea is introduced and two-stage ALT model is constructed to connect the failure distribution of products under different stresses. The model parameter estimation analysis is carried out based on the maximum likelihood estimation (MLE) theory under time censoring. The MLE, asymptotic confidence interval and Bootstrap confidence interval of the model parameters are obtained. The Monte Carlo simulation and the two-stage ALT data of a certain type of electrical connector are used to verify the model. The results show that the proposed model can effectively describe the life distribution of products in the two-stage ALT, reflecting the influence of the first stage test on the second stage test, whose life prediction accuracy is higher than that of the single-stage ALT model. The proposed model provides a new idea for the ALT research of products containing multiple task stages. © 2025 Chinese Institute of Electronics. All rights reserved.