A new class of multi-stress acceleration models with interaction effects and its extension to accelerated degradation modelling

Most products operate under multiple stresses. The influences of multi-stress factors on products are commonly not independent and promote a more violent degradation through interactions, referred to as stress interaction effects. However, few studies consider such effects in multi-stress acceleration models, which may reduce the extrapolation precision and further lead to an inaccurate reliability assessment. In this paper, a new class of multi-stress acceleration models with interaction effects is designed to extrapolate more accurate reliability metrics under multi-stress operating conditions. The main stress effect terms are determined by two criteria: physical stress-based ageing law and statistical correlation. The interaction effects are interpreted as the influences of other stress variables on the main stress effects. In particular, the explicit functions of interaction effects are alternative, which can be identified by adaptive optimization using the maximum likelihood criterion. Furthermore, this multi-stress acceleration model is extended to an accelerated degradation model by integrating a generalized Wiener process with nonlinear time scale functions and random effects. The acceleration factor constant principle is utilized to identify the stress-dependent parameters, facilitating a more appropriate model development. Finally, simulation and a real-world case are performed to validate the effectiveness and practical values of the proposed model.